Just found this on the MySQL site:
Posted by John Bissell on July 2 2005 4:09am [Delete] [Edit]
A note for Windows 2000 users (Office XP Developer,Access XP, odbc-connector 3.51.11-2) - after installing the "Update Rollup 1 for Windows 2000 Service Pack 4 (KB891861)" every attempt to update or add linked odbc tables crashes Access (using the existing data link seemed fine). They updated msjet40.dll (7/19/2004), and it seems to not play well with the odbc program. Replacing the dll with the previous version (3/1/2004) fixed the problem.
Answers some questions!!