There are two things that can be causing this and Lambchops is right about one Machrosync also called Machrovision and the other possibility is NTSC/PAL and whether your equipment is able to play both formats. You can buy a unit that fits between the playing unit and the recording unit that sorts out the Machrosync problem by replacing a new pulse sync signal which is good if you are going VHS to VHS as well. As for the NTSC/PAL compatibilty just check the handbooks for your gear they will tell you if that is the problem. Hope this helps
