I had the same problem and used capture now to get some of the video into FCP, however I still got the error message and not all of the video could be captured.
Just out of curiosity, what camcorder and type of tape was the problem tape shot on? My problem tape was shot on a Canon H1 in DV mode (TDK DV tape). Subsequent captures using DVCam tape shot on a Sony DSR 450 were not problematic.
Lee