Have you tried re-loading your Axim from scratch (erases EVERYTHING on it) with a ROM image on a SD card using the trick where you hold down Power and WiFi buttons and then tap the reset button on back?
This may be considered a last resort, but if you've tried everything else, you might reach this point. I'm not sure where on this site the procedure is documented but I can try and dig for it if you need help.
You basically load a couple WM50*.nb0 files onto a FAT32-formatted SD card, stick the SD card in, perform the Power-WiFi-Reset "trick" and then follow the boot loader instructions.
Fair Warning, however, from what I've heard if you're not careful this could "brick" your Axim (which is why I say this might be a last resort for you). I haven't had problems doing this with mine. The biggest thing is to make sure you are on AC power as the load can take over 20 minutes to complete.
Thanks,
mike@slavis.com