cielo009, At the moment it is not possible to extract 9.0.48 & 9.0.50 firmware so you could not have backed up anyway.
Your problem is going to be trying to find a firmware suitable for your player. Because they can not be extracted there are only a handful of factory versions available on the web. Forget trying 3.5.XX series firmware they are not going to work. You could try 9.0.43, 9.0.48, or 9.0.50 that suit your screen size.
http://www.mympxplayer.org/actions-9...mare-dc37.html
If none work you will have to wait till the updated tools for extracting 9.0.XX firmware are released then there will be a lot more for download.