I had sh!tty luck with the EOS software that came with my 7d...however, I downloaded the latest EOS utilities from Canon's site (Updated Picture Style Editor, DPP and EOS utility)...2 of the 3 were more recent versions than shipped with my 7d. Not sure if they've been updated since the Snow Leopard release, but it makes sense.
Try the direct D/L from Canon's site for DPP and see if good things happen. Also, Aperture and Adobe have both updated RAW support this past week for the 7d.