excel vba - Endless VBA Loop UNLESS I step through the code

I have a userform with 6 list objects. All of the list objects have named range rowsources. Clicking any one item in any one list will reference a chart on a spreadsheet and clear contents of any item's cell that does not belong with what was selected (explained better at the bottom of this, if you're interested). All of my list objects only have "After Update" triggers, everything else is handled by private subs.

Anyway, there's a lot of looping and jumping from list to list. If I run the userform normally, it endlessly loops. It seems to run through once, and then acts as though the user has again clicked the same item in the list, over and over again.

The odd thing is, if I step through the code (F8), it ends perfectly, when it's supposed to and control is returned to the user.

Does anyone have any thoughts on why that might be?

EDIT: I didn't originally post the code because all of it is basically a loop, and there's 150+ lines of it. I don't understand how it can be the code if stepping through makes it work perfectly, but allowing it to run regular makes it endless loop. Anyway, here's the code:

Option Explicit
    Dim arySelected(6) As String
    Dim intHoldCol As Integer, intHoldRow As Integer
    Dim strHold As String
    Dim rngStyleFind As Range, rngStyleList As Range

Private Sub UserForm_Activate()
    Set rngStyleList = Range("Lists_W_Style")

    Set rngStyleFind = Range("CABI_FindStyle")
End Sub
Private Sub lstStyle_AfterUpdate()
    If lstStyle.ListIndex >= 0 Then
        arySelected(0) = lstStyle.Value
        Call FilterCabinetOptions(Range("Lists_W_Style"), Range("CABI_FindStyle"), 0)
    End If
End Sub
Private Sub lstWood_AfterUpdate()
    If lstWood.ListIndex >= 0 Then

        arySelected(1) = lstWood.Value
        Call FilterCabinetOptions(Range("Lists_W_Wood"), Range("CABI_FindWood"), 1)
'        lstWood.RowSource = "Lists_W_Wood"
    End If
End Sub
Private Sub cmdReset_Click()
    Range("Lists_S_Style").Copy Destination:=Range("Lists_W_Style")
    Call RemoveXes(Range("Lists_W_Style"))
    Range("Lists_S_Wood").Copy Destination:=Range("Lists_W_Wood")
    Call RemoveXes(Range("Lists_W_Wood"))

    Range("Lists_S_Door").Copy Destination:=Range("Lists_W_Door")
    Call RemoveXes(Range("Lists_W_Door"))
    Range("Lists_S_Color").Copy Destination:=Range("Lists_W_Color")
    Call RemoveXes(Range("Lists_W_Color"))
    Range("Lists_S_Glaze").Copy Destination:=Range("Lists_W_Glaze")
    Call RemoveXes(Range("Lists_W_Glaze"))
    Range("Lists_S_Const").Copy Destination:=Range("Lists_W_Const")
    Call RemoveXes(Range("Lists_W_Const"))
    Range("Lists_S_DrawFrontConst").Copy Destination:=Range("Lists_W_DrawFrontConst")
    Call RemoveXes(Range("Lists_W_DrawFrontConst"))

End Sub
Private Sub FilterCabinetOptions(rngList As Range, rngFind As Range, intAry As Integer)
    Dim intListCntr As Integer, intFindCntr As Integer, intStyleCntr As Integer
    If intAry = 0 Then
        Call FindStyle(arySelected(intAry))
    Else
        'Save the List item.
        For intListCntr = 1 To rngList.Rows.Count
            If rngList.Cells(intListCntr, 1) = arySelected(intAry) Then
                rngList.Cells(intListCntr, 3) = "X"

'                Call RemoveNonXes(rngList)
                Exit For
            End If
        Next intListCntr
        'Save the column of the Find List.
        For intFindCntr = 1 To rngFind.Columns.Count
            If rngFind.Cells(1, intFindCntr) = arySelected(intAry) Then
                'Minus 2 to allow for columns A and B when using Offset in the below loop.
                intHoldCol = rngFind.Cells(1, intFindCntr).Column - 2
                Exit For

            End If
        Next intFindCntr
        'Find appliciple styles.
        For intStyleCntr = 1 To rngStyleFind.Rows.Count
            If Len(rngStyleFind.Cells(intStyleCntr, intHoldCol)) > 0 Then
                Call FindStyle(rngStyleFind.Cells(intStyleCntr, 1))
            End If
        Next intStyleCntr
    End If
    Call RemoveNonXes(rngStyleList)

    Call RemoveNonXes(Range("Lists_W_Wood"))
    Call RemoveNonXes(Range("Lists_W_Door"))
    Call RemoveNonXes(Range("Lists_W_Color"))
    Call RemoveNonXes(Range("Lists_W_Glaze"))
    Call RemoveNonXes(Range("Lists_W_Const"))
    Call RemoveNonXes(Range("Lists_W_DrawFrontConst"))
End Sub
Private Sub FindStyle(strFindCode As String)
    Dim intListCntr As Integer, intFindCntr As Integer
    For intListCntr = 1 To rngStyleList.Rows.Count

        If rngStyleList.Cells(intListCntr, 1) = strFindCode Then
            rngStyleList.Range("C" & intListCntr) = "X"
            Exit For
        End If
    Next intListCntr
    For intFindCntr = 1 To rngStyleFind.Rows.Count
        If rngStyleFind.Cells(intFindCntr, 1) = strFindCode Then
            intHoldRow = rngStyleFind.Cells(intFindCntr).Row
            Exit For
        End If

    Next intFindCntr
    If Len(arySelected(1)) = 0 Then Call FindStyleOptions(Range("CABI_FindWood"), Range("Lists_W_Wood"))
    If Len(arySelected(2)) = 0 Then Call FindStyleOptions(Range("CABI_FindDoor"), Range("Lists_W_Door"))
    If Len(arySelected(3)) = 0 Then Call FindStyleOptions(Range("CABI_FindColor"), Range("Lists_W_Color"), Range("Lists_W_Wood"))
    If Len(arySelected(4)) = 0 Then Call FindStyleOptions(Range("CABI_FindGlaze"), Range("Lists_W_Glaze"), Range("Lists_W_Wood"))
    If Len(arySelected(5)) = 0 Then Call FindStyleOptions(Range("CABI_FindConst"), Range("Lists_W_Const"))
    If Len(arySelected(6)) = 0 Then Call FindStyleOptions(Range("CABI_FindDrawFrontConst"), Range("Lists_W_DrawFrontConst"))
End Sub
Private Sub FindStyleOptions(rngFind As Range, rngList As Range, Optional rngCheckList As Range)
    Dim intListCntr As Integer, intFindCntr As Integer

    Dim intStrFinder As Integer, intCheckCntr As Integer
    Dim strHoldCheck As String
    Dim strHoldFound As String, strHoldOption As String
    'Go through the appropriate find list (across the top of CABI)
    For intFindCntr = 1 To rngFind.Columns.Count
        strHoldOption = rngFind.Cells(1, intFindCntr)
        strHoldFound = rngFind.Cells(1, intFindCntr).Offset((intHoldRow - 1), 0)
        If Len(strHoldFound) > 0 Then
            If rngCheckList Is Nothing Then
                For intListCntr = 1 To rngList.Rows.Count

                    If rngList.Cells(intListCntr, 1) = strHoldFound Then
                        Call AddXes(rngList, strHoldFound, "X")
                        Exit For
                    End If
                Next intListCntr
            Else
                intStrFinder = 1
                Do While intStrFinder < Len(rngFind.Cells(1, intFindCntr).Offset((intHoldRow - 1), 0))
                    strHoldCheck = Mid(rngFind.Cells(1, intFindCntr).Offset((intHoldRow - 1), 0), intStrFinder, 2)
                    intStrFinder = intStrFinder + 3

                    For intCheckCntr = 1 To rngCheckList.Rows.Count
                        If strHoldCheck = rngCheckList(intCheckCntr, 1) And Len(rngCheckList(intCheckCntr, 3)) > 0 Then
                            Call AddXes(rngList, strHoldOption, "X")
                            intStrFinder = 99
                            Exit For
                        End If
                    Next intCheckCntr
                Loop
            End If
        End If

    Next intFindCntr
End Sub
Private Sub AddXes(rngList As Range, strToFind As String, strX As String)
    Dim intXcntr As Integer
    For intXcntr = 1 To rngList.Rows.Count
        If rngList.Cells(intXcntr, 1) = strToFind Then
            rngList.Cells(intXcntr, 3) = strX
            Exit For
        End If
    Next intXcntr

End Sub
Private Sub RemoveNonXes(rngList As Range)
    Dim intXcntr As Integer
    For intXcntr = 1 To rngList.Rows.Count
        If Len(rngList(intXcntr, 3)) = 0 Then
            rngList.Range("A" & intXcntr & ":B" & intXcntr) = ""
        Else
            rngList.Range("C" & intXcntr) = ""
        End If
    Next intXcntr

End Sub
Private Sub RemoveXes(rngList As Range)
    rngList.Range("C1:C" & rngList.Rows.Count) = ""
End Sub

Explanation:
Imagine you had 6 lists with different automobile conditions. So Make would be one list with Chevy, Ford, Honda... Model would be another with Malibu, Focus, Civic... But you'd also have Color Blue, Red, Green... So if your user wants a Green car, the program references an inventory list and gets rid of any Makes, Models, etc... not available in green. Likewise the user could click on Civic from the Model list and it would elminate all but Honda from the Make and so on. That's what I'm trying to do anyway.

Answer

Without seeing the code it's tough to tell. When you run the script, the 'AfterUpdate' event may be getting triggered over and over, causing the endless loop. Try using a counter to limit the update to one change and have it exit the loop once the counter is greater than 0.