MBP 17" 4,1 2.5 Penryn Photoshop CS4 screen glitches

[ienes]

Hello,

I've ran into this trouble lately:

http://img21.imageshack.us/img21/5893/glitchz.jpg

It happened when I pressed TAB key in order to hide all the palettes.

Switching to other opened document and going back did the job and the glitch was gone.

This is from Adobe Photoshop CS4, using Leopard 10.5.6 and MBP 17" 2.5 Ghz Penryn (the last one before Unibody).

The question is: is this a hardware issue or CS4 bug (I have GPU acceleration enabled)?

Any help appreciated,
Regards

 

[alphaod]

Looks like hardware since I don't have that issue and I have the GPU enabled.