Denon DVD-3910 Firmware and Issue

This is what I have currently:

ESS 6609-A Firmware

I wonder if you can help. I finally was able to get my DVD 3910 up and running after many years, but only have -A SW. Denon site is not supporting downloads of this DVD player (What is the big deal of leaving FIRMWARE on the site??).

I am having intermittent issues when I play DVD-Audio tracts. When some songs are being played, they that are distorted, skipping pieces of the music or not playing any music at all! Many of the tracts sound great, but almost every disk I burn, there is any issue with songs that are messed up.

Also, it seems that I cannot play any MP3 formats on CD. Is that supposed to work? Maybe I am burning the CD wrong?

I have played these "bad" tracks on my PC DVD player and ALL are recorded with issue.

I was hoping someone can help with a firmware upload because that is where everyone starts. I would rather not think it is the transport or the optics (I have taken the unit apart and cleaned the lens).

I have read that the last SW that I can confirm is 6609-D. I also read that there seems to be a version 6609-E? I am assuming this firmware is for USA.

I would appreciate any ones help for the firmware upload very much!

Thanks to all who can help.