I would be tempted to uninstall the new version and reinstall an old one--at least until you have time to figure out what is the problem. I have no idea.

Though I will say that I'm kinda annoyed at Adobe. When I bought my new computer...earlier in the year, I had to upgrade to CS4, since my old Mac was a PPC model and the new one is Intel. My old CS2 wouldn't run on the new machine.

So I upgrade to CS4 and those jerks released CS5 just weeks later. The least they could have done was give me a heads-up. I could have managed a few weeks without Photoshop and waited for the next version.