October 29th falls between the last Sunday in October and the first Sunday in November. After 2007 the end of Daylight Savings Time changed from the last Sunday in October to the first Sunday in November. Any chance one of the computers didn't get a DST patch from MS? My brain is not ready for any kind of math calculations and I can't say for sure which computer that may be.
Daylight Saving Time Help and Support Center
http://support.microsoft.com/gp/cp_dst
EDIT: Just reread your post that says no other meetings are affected on October 29th. Not sure what the problem could be if user A creates another meeting for a different time on the 29th and User B sees it as the same time.