VS2010 debugger debugging old code

I have a console app, and a class library.

I'm making changes to the class library (adding new methods, changing what methods do, etc) - Just regular stuff - nothing fancy.

In the console app - I'm calling methods from the class library - obviously to test the class library methods - again no rocket science here!

Both projects are targeting Framework 3.5 (This is because I have Sharepoint 2010 being referenced in class library)

Now:

When I debug the app using F5 - I've set a break point in the console app. When it steps through to the class library (using F11) I get a message saying source code has changed in a pretty lengthy dialog. If I click cancel - it then says No source code available.

I have found a work around to right click on project in solution explorer, then select debug -> create new instance.

But this is strange, never had this issue before, what can I do to get the d开发者_运维技巧ebugger behaving normally. By normally I mean every time I hit F5 it should understand that the source code in the class library will almost surely have changed and I don't want any nags about this, or break point conditions never being met.

On a side note, never had this issue before, so an explanation as to why its happening would help a lot.

Thanks in advance

Update: the short version

Why do I have to manually tell the debugger to "create new instance" everytime I want to debug? If I don't hitting f5 debugs the source code of the last successful debug session.

Maybe your console application doesn't build second project? Try verifying that newest version of library is called.