For me it automatically is in sync when I record. If your audio/video is out of sync, I would assume that there might be a resource issue. I am not a techie, but on the 2 computers I have, I am recording fine from VHS using the hardware that the program came with. You might need to check with magix technical support to make sure.
Also, make sure you are not running any other software programs. Every icon that is located near the clock of the computer is a program running in the background, those reduce your resources dramatically.
In Magix Video Edit Pro, when I did some sound editing, and then did a playback, the sound was out of sync. When I exported to a file, it was in sync. Maybe the same with Rescue. Don't know, but maybe worth a test.