Probably should have tried out the 1 month free trial, on any program they offer from Adobe to see if it works for you.
I find it hard to believe that Aperture won't work well with your mac... yet it should be leaps and bounds better than the software Nikon provides with their cameras (poke at Nikon vs Canon).
At any rate, I hope it is as simple as an update for you to get things worked out...this stuff shouldn't happen with Macs.