Sorry about the delay in reaching you. I’ve been spread really thin between projects.
At the very least, song ratings programmed from the user interface on the player should be retained. Strange things are possible with synchronizing with the computer, but that side of the equation has a different set of issues.
Just to play devil’s advocate, I tried tinkering with song ratings using the Clip Zip. Like you, I have found song ratings to be useful. On this player, I have a microSD card mounted, so I can test both memory areas for proper function. Success. Song ratings are retained and changes are saved.
If your player is losing the ratings, following a normal shutdown of the player, it’s possible you have a glitch in your firmware installation. 01.01.20 is installed on my device, so I am quite sure it can work. I tried plinking the ratings on some MP3 and AAC (M4A) tracks to be sure.
What you can do is reinstall version 01.01.20 manually on your device. The Sansa Updater only upgrades, but doesn’t have the capability to reload the same firmware over an existing one of the same build.
Here’s the link to firmware 01.01.20. Follow the directions following Manual Firmware Update. Be sure to unzip the bin file before transferring to the Clip Zip. It should say “firmware Upgrade In Progress” upon disconnect.
Let me know if song ratings work after reinstalling the firmware.