From: Brentwood, California (not the OJ one)
I do not have the unit list open, but I do have detailed tooltips toggled on. However, the mouse lag is noticeable right away at the main menu screen, even before getting into a game. It is laggy on every game screen, scenario selection, troop selection, multiplayer lobbies, etc.
It is the same with BA2, so it must be an inherent issue with the game engine. Again, it's not too bad, just annoying that it is not as responsive as the Windows mouse.