DVD player plays upsidedown!?

I have an 8in portable DVD Player, PDM-0821. The picture plays upside down...I have used the directional keys as instructed inthe Operational Manuel but so far, no luck...It played properly the first time, then it just changed and nothing I press will make it right. What can I do?
I have been confined to bed it the DVD player helps pass the time, but it is getting increasingly difficult to play upside down, turn around, etc, in order to make the remote work...HELP me if you can!