I've used Capture One Pro and Canon Utilities for tethering 1Ds3's and 5D2's and both softwares have proved to be a constant source of embarrassment in front of clients due to lost frames, freezes, crashes and general poor performance even on new apple laptops. For the last few weeks I've been using DSLR Assistant including a Beta of 1.5 and not only are there a load more features, most importantly it's way way way more stable as a tethering solution. I'd advise people with similar experiences to switch off tethering in C1Pro and allow this dedicated software to handle this crucial task.