First, I don't believe there is a Canon 2000x model. That sounds like Canon's digital "zoom factor" on the FS-series, DC-series and other camcorders. What are you using ... an FS10, FS100, other model?
Second, are you using an external FW drive? If so, that's the reason you are getting interruptions. If you are using a camcorder with FW connection (usually a miniDV camcorder, especially Canons) then you really have to connect ONLY the camcorder to your Mac, and capture to your internal drive. Don't daisy-chain the camera with an external FW drive - that's the source of lots of capturing problems.
Third, your profile indicates you are using FCE on Lion (10.7.2) ... FCE is not supported on Lion. Was FCE already installed on your Mac before you upgraded to Lion? That could also be a source of capture problems.
My capture scatch folders are in Users>Documents> Final Cut Express Documents>Capture Scratch, and also stand alone folders, as Capture Scratch. When you move your project from the internal disk to the external disk unless you bring the capture scratch files for that project it will remain on the internal disk. You may have to reconnect to the project.