Capturing footage from a tape that has had a different format previously recorded on it will not work in Final Cut Express HD.
For example, if you previously recorded a project onto a tape using a 720p30 format camera, you shouldn't use a 1080i60 format camera to record over the footage on that same tape (or vice versa). Likewise, a tape that you previously used with a DV-NTSC camera should not be used again with an HDV camera.
If you do try to capture footage from such a tape, you may experience the following issues in Final Cut Express HD:
You can reuse a tape (despite its format history) without issue if you have a way to "black and code" or stripe the tape with the format you want to use (Final Cut Express does not offer a way to do this).