This feels very magic and apparently I'm not the wizard I'd like to be.
I have a web service that I debug in the local asp.net dev server. The mstest unit tests work fine on Windows XP, but when I build and test on a Windows 7 machine, the web service code does not write the log it's supposed to, to disk.
When I tried adding an explicit Directory.CreateDirectory(@".\TestDir") call to the unit test code and stepped in the debugger, I could see the folder appear. But when the test was done, the folder was gone.
Also, when I create a directory explicitly in the server code and step in the debugger, I cannot see the directory being created, but I don't get any exception either.
I use visual studio team system 2008 for developers.
The problem went away when I installed SP1 for Visual Studio. I was given a new machine and missed that it wasn't updated...