Needhelp , i could not find any v9.1.50 firmware in the downloads section. However, there are the v9.0.xx series which you can try.
http://www.mympxplayer.org/actions-9...mare-dc37.html
If they do not work, i'll suggest that you contact your seller if an exchange if it is still under warranty.
Also, you can try asking your seller if they have the firmware to send to you.
Search the CD that came with your player, sometimes the firmware is inside. It should be in .fw or .bin format.