I am running Photoshop CS under 10.2.6.
I have not had any problems.
Before installing new software it's good practice to run
Disk Utility and run repair permissions.
You may want to uninstall Photoshop CS.
Run repair permissions and then re-install Photoshop.
I am also a big fan of Alsoft's Disk Warrior 3.0 for fixing Macintosh problems.
You boot from Disk Warrior's CD while holding down the C key. It examines and repairs the directory
structure of a disk. It has helped with several different problems.
It costs $79.95. A day of lost work due to a badly performing Mac is worth 80 bucks in my book.
Buy it on disk, the downloaded version isn't as versatile.
http://www.alsoft.com/DiskWarrior/ http://www.clubmac.com/clubmac/shop/...sp?dpno=148024
Micromat has just released Techtools 4, which promises to be a useful OS X utility.
http://www.micromat.com/tt_pro_4/tt_pro_4.html
I have had good experiences using Techtools 3 with OS 9 computers.
Like it or not, as digital photographers we have to become our own computer troubleshooters.
Good luck.