Andy's guess that the issues on Windows have to do with its limitation on command length appears to be a good one. With a web search I find this, for example:
"When I launch our application in Eclipse on Windows I receive the following error:
Exception occured executing command line.
Cannot run program .. : CreateProcess error=87, The parameter is incorrect
I've solved this in the past by shortening the CLASSPATH.
I've now come to a point where I can no longer shorten the CLASSPATH, and would like to know if there are any other workarounds.
http://support.microsoft.com/kb/830473 seems to indicate that the max command prompt line length in windows xp is 8191 characters, and the only solution is to shorten folder names, reduce depth of folder trees, using parameter files, etc."
exectck displays the command line for each test, so we can check that and see what might be truncated for the failing tests.