I've successfully got PartCover 2.3 working with VS 2008 on my 64-bit machine.
I'm now trying to get it to work with VS 2010 and NUnit 2.5.3. I've got NUnit using the correct CLR version, but I can't get PartCover to produce any output. All I get is an "empty" report XML file:
<PartCoverReport date="2010-03-30T16:09:05.1009099+01:00" />
How do I get PartCover 2.3 (or 2.2, I guess) to work with NUnit 2.5.3 on .NET 4.0?
I have recently completed a portcover fork that will hook into the .NET4 CLR - maybe you could give that a try
http://github.com/sawilde/partcover.net4