I find xUnit to be an essential tool; and I wish to thank you for and congratulate you on its creation.
Further to Arthur's comment of 02 Feb 2010, I too have experienced similar issues; specifically, when attempting to compare strings that contain escape characters. For example:
function test_suite = temp
assertEqual( 'C:\', 'D:\', 'message.' );
Rather than trying to escape the escape-characters, I would suggest modifying the calls to the "MException" constructor within assert*.m, so that the messages get passed as a string parameter rather than as the format string itself. For example, the following: