Iphoto compatibility with Photoshop. Need Help!

Ok, I've made the switch! Yay! But I've encountered one big problem......

I imported my wedding photos which had been previously edited using a windows based pc and more precisely adobe photoshop or Creative Suite (not sure), and the can't be read by my mac.

In iphoto , when you browse the photos in events, the file is there but does not appear as a miniature preview ...............they look blank..............and when you click to open, the photo appears very strange as if there are several layers overlapping?

I recently tried editing some photo's using Photoshop from Creative Suite and encountered the same problem when I imported them into my library. The do not show up. I do remember that all the photo's in question were black and white. (hope that helps...)

I'm assuming it's a compatability issue with Adobe?

Is there anyway I can fix this? Anything I need to add to my mac so that it'll read those files properly?

If anyone can shed some light on this problem, i would be very grateful.

First of all, how did you import your photos to iPhoto? Did you just drag and drop from your PC to your mac? If so, that is the problem. You must "import" them via iPhoto. If you did import via iPhoto, perhaps a rebuild would help. I do remember seeing some posts about people having problems with B&W photos, so you might research that. Photoshop and Creative Suite should not be the problem, since many mac users use these very programs.