Nope the module isn't remembering the changes (backup battery is dead) but I'm quickly learning the menus as I'm having to put in the volume adjustments every time I turn it on!
The pad model numbers / 'types' are correctly found in the TD-8, so each module is reporting is correct model number inside the TD8, i.e. channel 1 is kd-8 for instance.
I'm doing some reading through the TD8 manual PDF and searching for 'volume', 'low volume' etc doesn't bring up anything useful ... this is strange. I've found some other forums with someone who reported the same issue but no one was able to fix it, I also followed the instructions they suggested;
http://acapella.harmony-central.com/showthread.php?t=2030735