This is a known bug with the new Beta Firmware. The only solution is set the Primary Output to COMPONENT. This will force the decoder to do all aspect ratio control (which will be correct) rather than the ABT (which will be incorrect).
You will want to change the Primary Output to HDMI whenever playing DVDs, however, as the decoder will not do as good of a job de-interlacing and scaling as the ABT solution.
Best Regards,
Customer Service