It's no news that games ship with some bugs in them. The same goes for the Sims 2 on the Mac. Aspyr has released a third patch for the game. This patch solves a conflict with NVidia video cards in combination with OS X version 10.4.3. The patch also includes the fixes for the previous two patches, so you don't need those for this patch. You can download the patch from MacGameFiles. For a full list of fixes, including those of the previous patches, check Aspyr's patch page.