That can be a sign that your display driver is buggy.
Is your system a PC? If so, what video card do you have?
If it's an ATI card, your best bet right now for stable Photoshop operation is not their latest release, but their latest beta version: Catalyst 13.3 beta 3.
Hallo! Thank you for your reply kind sir. I'm using notebook.
Here are the details of my graphical card:
ATI Mobility Radeon HD2400
Chip Type: ATI Radeon Graphics Processor (0x94C9)
DAC Type: Internal DAC (400MHz)
Total Memory (884 MB)
Display Mode: 1280 x 800 32 bit 60Hz
So what should I do now?
It's in a notebook, so you may have to go to the web site of the maker of the notebook for updated drivers. Desktop users can usually go to AMD.com for updated drivers.
If you're given a choice, ATI Catalyst 12.8 or 13.3 beta 3 are the best choices (as of today) for Photoshop.