Adobe Premiere CS5 DV Capturing Issues

Hi! I've really searched the internet to find someone with the problem I have and I unfortunately failed. Please help me if you know anything about solving this issue.

So.. I can capture video when I connect my camera to my iMac (via firewire), but every new clip I capture has a different resolution and often low quality sound. I'm recording in 16bit, while the program sometimes captures in 12 or 8bit. It doesn't make sense. Is iMac from end 2010 too modern to capture DV footy properly? I somehow doubt, but I had to ask anyway. Since I don't have my PC around, I have to wait for weeks to go back home (another city) to capture all the footy in Windows where there is no such problems.

I hope you can help me! Thanks in advance!

Dino Sertovic