>Did you apply the services packs to your Office installation ? I remember SP1 corrects problems with PPT. There are 2 SPs at Microsoft site to download. They must be applied from 1 to 2.

Actually, there's no need to apply the SR1 patch before applying the SR2a patches; the SR2a patch file contains all the fixes from SR1. You are correct, though, that if you've already applied SR2 or SR2a, you can't go back and apply SR1.