I called up Adobe Support. I was also having a load and hang issues. They told me to:
1. Uninstall and deactivate.
2. Use the CS5 removal tool
3. Re-install
4. Do not do a software update (the technician has no faith in his own updates).
5. Swinging a dead chicken is optional
It fixed most of the problem but CS5 still hangs with larger files. CS5 is an unstable piece of junk. You’d figure they have a stable movie editing system after all of these years.
Good Luck Justin