Running both external HD and capturing from camera..?

I'm looking to get an external Hard drive for video editing. I have a WD My Mook Studio 500gb. I haven't had any problems with it...however I'm not able to hook my camera up to my mac while using the external. I wanted to be able to capture video directly to the external. The camera would use one firewire port and the external the other.

I have a Macbook Pro 15" and its a few years old..made in 2007 I think.

Is it possible to run both of these at the same time using another method? Or is there a better external that could handle it?

What happens is I plug my camera in and when it recognizes it the external just disconnects.

Not sure as to whether it's possible over Firewire. However, I have done this with a combination of both Firewire and USB. I had the camera input coming in through Firewire and I had the hard drive hooked up via USB. Worked like a charm.

Will capturing using USB lessen the video quality or drop frames you know?

I didn't experience any loss, but then again, I wasn't transferring HD quality video. If you are, then it's possible.