I had a similar problem. My new computer does not have a firewire port, so I was not able to capture some MiniDV content using the firewire controls. I was, however, able to capture the content manually by plugging the camcorder into the USB port and setting the camcorder into "VCR" or "playback" mode. Just start your editing program and set it to "capture video" mode. Locate the camcorder under "available devices" (or whatever equivalent procedure your program uses). Then hit "Play" on the camcorder and "record" on your capture screen. You, unfortunately, will have to manually split the video content later in the editor, but it's better than nothing.
Alternatively, you can always send the tapes in to have the content recorded onto DVDs. Your local photo or video shop should be able to provide the name of a local service. Or you can always find one online. Also, Costco provides this service as well.