This sounds as if the image window is off-screen. Have you disconnected a second monitor, or changed desktop resolution, or tweaked some other display setting?
Make sure you have installed the patch for CS5 from here: http://www.adobe.com/support/downloads/detail.jsp?ftpID=4733
And update your video drivers from the card manufacturer's web site.
Sounds like you installed 64 bit version of CS5. I don't have a direct solution, but only a workaround, which helped in my case.
(see thread below): Install 32 bit version of CS5 and hope with a later patch from Adobe the problem will disappear, however not very likely for Vista.
The 64 bit version of CS5 works just fine.
If it is not working fine, then you have a video driver problem. For your nVidia card, visit this site to check for updated drivers:
Answer to Noel Carboni:
Thanks for your suggestion. I installed the most recent driver, but it did not help.
If I open a psd file the background is empty unless I set the zoom scale to 25%. For any other zoom ratio I get an iakiramemashitamage only as long as a move the file with mouse. If I stop and deppress the mouse button it disappears. Never seen such strange behavior. The 32 bit version works normally.
akiramemashita (japanese)= I've given up.
Try disabling SLI. If that doesn't help then go to Edit->Preferences->Performance->Advanced Settings and try changing the Mode dropdown. If that doesn't work then you'll probably need to disable OpenGL Drawing from Edit->Preferences->Performance.