Conversion 8mm tapes to computer/DVD

HI, hoping someone can help. I have a LOT of 8MM tapes that I want to get to my computer so I can make DVD's. Trying to make this short, but I bought a converter, and it seemed to work...except that the video was "jumpy" after capturing. So, another forum suggested that I do it with a digital recorder, (which my Father has) and get a firewire cable. Great, I thought...I got the cable, and now I see that my Father's video camera has the "mini" tapes and I have the full-size tape. I thought I could maybe use it as a "pass-through", but it it not working. I am so darn frustrated, because my Mom passed away last year and I want to save these videos of her. Any ideas? The capturing software I was using is Corel VideoStudio Pro X5. In the beginning, I thought I could use Microsoft MovieMaker, but it does not recognize the converter (Startech S-Video / Composite to USB Video Capture Cable). Any help would get GREATLY appreciated!

==Wendy