Actually your problem may lie with a well known issue with Liteon dvd recorders.
I believe the A760GX only records analogue signals.
Essentially Liteons translate analogue signals (analogue TV, RF/scart output from a VCR etc) into digital signals. Virtually all analogue sources were designed for the old 4:3 TV standard.
However, with freeview/sky boxes you can actually record a 16:9 source but the keypoint is that the freeview/sky box converts it to an analogue 4:3 signal (squeezing picture horizontally. As far as the liteon is concerned the signal is analogue and assumes 4:3.
If you examine the ifo files burnt onto a DVD by the recorder using IFOEDIT (freeware) I am sure you will see that the dvd is marked as being 4:3 format.
You can change the IFO file using IFOEDIT and mark it as 16:9 (rip to PC, change ifo file, burn new DVD). This would then work. However this is only worth it if you are going to watch the DVD many times. Seacrh forums for post of mine, I explain how to do this elsewhere.
I do not know if the same applies to a recording played back from hard disk but given the weakness in Litons for DVD recorders, I wouldn't be surprised.