Help Problem with Liteon Clone (maybe)

I have two Lite on recorders - The LVW-5001 and The LVC-9006. Both work fine. Went over to a friends house to set up his Go Video R6750. It appears to made be liteon. It recordes from Cable input OK, but when AV-1 (front) is selected (Output from a old BetaMax), or AV-2 (rear), From a Go VCR recorer - The Dvd Recorder will only record for a SHort Time ie 6 to 40 Mins then Bombs out. The issue is not a copy protection issue. any Ideas, or has any one else (Lite-on 500x series, Or Go video system) had this problem