Help please.

I have an Apple iMac G5 with 2.5 gb memory. Run Leopard.

Last Saturday I received a brand new sealed version of Aperture 2 as a gift. Installed it and did the upgrade to 2.1.

My problem as follows.

Tried to adjust approx 100 RAW images, things went ok at first, however very slow, after 10 images I clicked on the next image in the browser. In the process of adjusting, it suddenly went black in the main screen. This happened intermittently to the rest of the images along with some images looking like a dark black negative. Subsequently just clicking on some browser images they would immediately bring it up black or with negative look in main screen.

The only way I can get the image to come up correctly is to get out of Aperture and back in again. Then the same events happen all over again.

I put some jpegs on and got through adjusting 60 and then the same events happened.

I removed Aperture and downloaded the trial, entered my s/n and tried again. Same situation.

Contacted Apple, tech rep stated never heard about this problem before, must be a computer problem. Maybe, however Aperture 1.5 worked fine. iPhoto 8 works fine. Photoshop CS2 works fine, as does everything else on this iMac. All worked great with Tiger and now with Leopard.

Does anyone have any idea what maybe causing the problem ? I am at my wit's end !!!!!!!!!!!

Thanks for the help,

Max.