For everyone that is having USB problems - first *make sure you are not using a hub!* Be CERTAIN that the Axim is plugged directly into the main USB port on the back of your computer.
After that, make SURE you have ActiveSync 3.6 installed. If you only have 3.5, stop now and go
here
If that still doesn't work, check the motherboard you are using and see if there are any updates. These are sometimes a bit tricky (you have to load the update onto a floppy and then boot from the floppy to flash/rewrite the new motherboard information) but it can solve a LOT of problems on a lot of systems with USB problems.
HTH,
Nick