When I run my C# WinForms project either by pressing F5 or clicking Start
button on toolbar, it sometimes doesn't execute the currently changed code
and runs previously compiled code and this strange thing happens occasionally
no matter its started in Debug or Release mode.

I have tried all the related options in VS Tools => Options => Projects and
Solutions => Build and Run, but its not solved. Sometimes it compiles the
fresh code and sometimes not so, I can't mention the exact steps to reproduce
the behaviour. This problem happened to me hundreds of times during
development of my current project so, there is no doubt in it. The only way I
found to workaround this problem is to renming the "bin" and "obj" folders.
It was so much frustrating because sometimes I am checking the effect of some
code but its actually not compiling it.

I had this problem in VS2005 and I was anxiously waiting for final release
of SP1 and recently after upgrading to SP1 this problem is still there as it
is.