TestResults not cleaned up

I'm using Visual Studio 2008 with ReSharper 4.x.  I've been using the ReSharper test runner exclusively since I rebuilt my workstation a few weeks ago.  I've noticed that in my test projects' output directories, there's a TestResults folder with hundreds of subfolders and files.  These are presumably the test result output for each of my test runs.  In one TestResults folder I had 200 subfolders consuming 400MB of disk space.

My Visual Studio 2008 preference is to keep only 25 past test results, far less than the 200 I observed.

So who's to blame: ReSharper?  Visual Studio 2008?

I found some blogs suggesting its Visual Studio and ways to fix it and another saying the Visual Studio limit should be working, but I'm looking for someone else to confirm/deny first:

http://blogs.msdn.com/ploeh/archive/2006/07/13/CleaningAwayTheTestResultsFolder.aspx
http://jaychapman.blogspot.com/2007/12/visual-studio-2008-test-result-cleanup.html