One thing left I think is to use WinDbg to try and debug it. Here are some links on how to use it:
- http://www.codeproject.com/KB/debug/windbg_part1.aspx
- http://blogs.msdn.com/johan/archive/2007/11/13/getting-started-with-windbg-part-i.aspx
- http://blogs.msdn.com/tess/ (good blog about debugging in general in windbg)
Thinking about it, it could also be some service or something that's clashing. Try stopping all unneeded services and closing unneeded programs (including startup ones) and see what happens then.
