VS 2010 Build problem

Sometimes Visual Studio is playing silly buggers and does not let you rebuild your C# project.
For avoiding this follow the instructions:
Project properties => Build Events
in Pre-build event put this:
if exist “$(TargetPath)” move “$(TargetPath)” “$(TargetPath).delete.%random%”
in Post-build event put this:
del “$(TargetPath).delete.*”

Problem solved