dr3am, if your player is 'dead' and needs 9.0.48 i might be able to help restore it in some capacity.
You could try all the 9.0.48 versions on the download section here for that sized screen first. I also know that this firmware file >
http://www.uxcell.com/public/MV-70A_1.zip is, at least partially, compatible with the ATJ2091H chips. I've restored a friends player to the point where it is playing mp3's again.. the screen is a little messed up but at least he has music. It will do until we can get our hands on a fully working firmware.
It says it's for a 1.5"inch screen but it is really for a 1.8" And the fw version is 9.0.49.
Give it a try