I have an MX700 which is an excellent mouse, but having read some reviews I did not install the Logitech mouseware drivers but instead have the mouse running on Microsoft intellipoint optical drivers. Never had much luck with Logitech drivers although I love their mice.
See this rather good review for details about the unpleasant things that can happen with the logitech drivers for the new MXs (good site this overall I find);
If you have the Logitech ones installed try Microsoft ones instead- I have not had any problems with them and am really pleased with the mouse performance, particularly in games. I have not had any errors or issues working in Maya (I am running XP).