I've found that when you are sorting columns, some do not sort properly.
For instance, if you go to the dashboard, My Referrer Sources, New, and you have times that are ranging from say a few seconds to 15 minutes, the column will sort the 10:xx below the 00:xx numbers. It's sorting text instead of a number I think.
http://img360.imageshack.us/img360/8214/20080714115743jr7.th.png
not a support question