c# - The breakpoint will not currently be hit. No symbols have been loaded for this document in a Silverlight application

Ok, what I have:

Visual Studio 2010 RC, W7 x64, started a new project type of Silverlight application. Hosting the Silverlight application in a ASP.NET Web Application Project. Silverlight Version 3.0.
Added a LinqToSQL Class, a WCF Service, a Winform Tester Application (Project in the Solution) and a few Classes (also as Projects in the Solution).

Yesterday, suddenly I got the 'The breakpoint will not currently be hit. No symbols have been loaded for this document.' message to appear in the IDE, but it only affects the Web Appliaction, I can debug the Silverlight and the Winform App.

What I tried / did to get rid of the message:

• Reset Visual Studio Settings


• removed all files in every \Temporary ASP.NET Files Folder (there is one for each 32bit/64bit and for Framework 2.0 and 4.0)


• tried to debug using Visual Studio Integrated Web server - normally I use IIS, in the project output of the solution I deleted every obj and bin folders in every project folder


• created a new solution and added all the projects to this new solution


• deleted the solution suo file


• created a new ASP.NET Web Application to test if it is a VS-installation issue => I can debug this new project/solution


• rebooted the machine several times


• repaired the vs.net installation


• did an IISReset



• removed the Web App from IIS


• used the Create Virtual Directory Button under Project Properties of the Web App to create a new Web App in IIS


• changed the Framework Version of every project from 3.5 to 4.0


• Opened the Solution on my second machine => same behavior


• crawled Microsoft Connect for bugs / similar issues


• SPENT 7 HOURS.

So, this happens the 2nd time in my life. last time I solved it by deleting Temporary ASP.NET Files Folder, but this time I need your help.