Why my Capture card is Dropping Frames?

Ok so I'm filming footage in Halo Reach. I'll be Capturing and i lose about 1000 frames for just 30 seconds. I've checked the cpu usage and it goes to 100% while the importer is up I've tried a lot to get this from stopping and it's hindering my Machinima Progress i need some advice on this. oh and I'm using a Pinnacle Studio movie box Capture card and Pinnacle studio 14