I've been using PSE 10 for a while on my OX S Mac. Processor 2.4 GHz intel core 2 duo, Memory 2 GB 1067 MHz DDR3, software 10.8.2.
It was not slow before but know it freezes up so much that it becomes nearly inoperable. I checked my memory and I have plenty of space. I shut down all the other applications. I boosted up the amount of RAM PSE can use. I decreased the amount of undo states PSE can keep. But even with all that, it still was slow. So I uninstalled it and reinstalled it, and that didn't fix the problem either.
Is there anything I can do to get it back to the speed it was at?
Go to your username>library>preferences and delete:
Adobe Photoshop Elements 10 paths
Adobe Photoshop Elements 10 settings
and any lockfiles with the same names.
That library is hidden in 10.8. To see it, option-click the Go menu in the finder. It will appear below the little house for your user account. While you're in there, go to the Saved Application States folder and delete everything for PSE.
Repair permissions and see if it's any better.
If adamhbrandt had more ram, that might help, but in my experience, even with double the ram available, upping that slider is a mistake unless you have plenty of other ram left over for the rest of the system and other running programs. With 4 GB putting it up just made everything else unuseably slow, too. Of course that was in 10.6, but anecdotally 10.8 wants a lot more ram than 10.6 did, from what I hear.