I have imovie 10.0.4
That's your problem..
I have moved a lot of video from Hi8 and VCR videotapes. There's a tad bit of work involved but once you acquire all the pieces you will get excellent results.
Moreover, your final result should be a DVD. That way you will have something you can watch for the next 30 years. You can certainly save the video in other ways too, but I would also see it through to a DVD.
I use iMovie HD 06 with iDVD 09.
Your workflow is editing DV clips and making DVDs, iMovie '06 is better suited. Your movie will arrive at iDVD in DV format, which is an ideal match for making a DVD: same resolution, same pixels, aspect ratio, and original quality.
iMovie 06 and iDVD 09/11 is a 100% "lossless" combination and my DVD's look like they came from Hollywood!
You will also need a A/D coverter. (Like the Grassvalley ADVC300)
I've played around with countless other conversion systems, ranging in price from $79 to $399. Short verison, this is the ONLY unit to own. No dropped frames at all, even with questionable quality tapes, no jitter, great color, excellent sound quality. Zero setup with iMovie 06 and iDVD 09/11.
This is a prosumer deck. The time code function is alone worth the price if you have old analog footage. Absolutely NO "Out Of Sync" audio.
ADVC300 is for anyone who wants to do editing and is concerned about quality of color and speed, for the novice it is an incredible gizmo that will restore VHS tapes to a state close to the original fixing midtones, highlights and shadows on the fly. Not only can you simply convert analog to digital you can actually manipulate the signal going in (if you want to).
Use Mac OS 10.6.8 if you can. (Newer OSs will work also but you will have to control the ADVC300 manually.)
A bit pricey but it WORKS.
The ADVC300 has been discontinued by the manufacturer. The included software (which is not really necessary but does enhance performance) is not compatible with OS 10.7 or newer. You can still find the ADVC300 for sale in a few outlets as well as eBay. It will sell between 50% and 100% ABOVE its retail price. Yes, it's that good.
If you can’t find the ADVC300, use the Grassvalley ADVC110.
Why use iMovie HD 06 ? iMovie 09, 10, and 11 uses 'single field processing' meaning every other horizontal line of the video is thrown out, which reduces the sharpness of the footage. iMovie HD 06 uses ALL of the image to form the video.
For maximum quality here is my procedure: ADVC300 > iMovie 06 > iDVD 09/11.
This may seem like more trouble than you want to go through. However, I find the superior quality to be well worth it.