I've merged this thread together with the cross-posted thread that was located in the Newbie forum. Please note that cross-posting is not allowed on this forum as someone may end up trying to help out on one thread, without realising that someone else has already provided the same advice on another cross-posted thread. Cross-posting is also not allowed under this forum's policy.
To me the problem seems to be copy protection reltaed as many copy protected VHS tapes would result in a recording with a varying brightness, loosing video sync, etc. By the Lite-on stopping after a short period of time also gives a clear indication of this as generally a Lite-On DVD recorder will not allow the recording of any source with copy protected signalling.
Just in case it is dirty heads in the Lite-On's VCR, I would recommend running a cleaning cassette in it, especially if you get a bad picture when playing back the tape in the Lite-On before making the recording. I would also suggest using a rewritable disc, such as a DVD-RW or DVD+RW for testing as these can be erased. Should you then find out a way to transfer the recording, then use a DVD-R or DVD+R.