Odd photoshop 'bug'?

[shiato storm]

Right, getting a weird thing happening with photoshop (CS4 ex), often when I open a new document, either a fresh one or open an image, the image is off-set by about 10 pixels, there is a white bar across the top of the frame and using a brush (of any type) results in a similarly offset accuracy.
I can get rid of it by hitting 'f' a few times (cycles through window modes) but its a pain to have to do so. just wondering if anyone else gets this at all? find a solution?

 

[Bagger]

CS4 now uses hardware acceleration,make sure you have the latest video card drivers installed.
May just resolve your problem

 

[shiato storm]

Yes I know it does, using a mac pro (08) and MacBook pro it still happens... Settings are fine, can't get my head round it