I just recorded this old commercial. Notice how the video starts at one point, and the audio a quick second later. When I click record, nothing happens, then a second or two later the recording indicator pops up. I'm assuming the video gets caught the exact second I press the record button, and the audio when the indicator says it's recording.
I do media archiving for an Australian rock band, so I have contact with other people that transfer VHS to PC conversions. They never seem to have a problem with their devices, and are running on PCs with much older technology.
Maybe this just isn't a good product (?) This is the second Roxio converter that I have gone through. The first one I had to return, as it was overheating and creating bleeps in my audio.