Need help with Final Cut Pro 4

Hello there,

I'm just starting out on this, had a few hours of tutorials and was about to attampt to editing, I was trying to capture video to my computer but while I did so, the capturing stoped and I got a pop up window that said " dropped frames have been detected"
I read something in the help menu that I should set the analogue data rate somewhere to 3 mb/sec, only I have no idea what that means nor do I know where to set this preference.
If you have any clue what, where and how, please help me out!

Thanks in advance!
Cheers