Actually, after looking into it more, I think that even a ROM update (on Dell's part) wouldn't be able to do it. The problem is the order of the virtual keycodes that are assigned to the hardware buttons on the Axim X3/X3i.
Most PPCs are assigned in this order: Calendar(1) - Contacts(2) - Email(3) - Home(4) - Record(5)
However, Dell has assigned the keycodes in this order: Record(1) - Calendar(2) - Contacts(3) - Email(4) - Home(5) - WiFi/WMP(6)
So as you can see, the software is calling the virtual keycode for Button 1, which on the X3/X3i is the record button. And the farthest right button that the software is calling is Button 4, which in this case is the E-mail button. The Home button on the X3 and the Wifi/WMP button are not able to be used, because they are Button 5 and Button 6. Dell definately messed up good on this one.
I'm almost positive that virtual keycodes are in the hardware circuit itself, so a ROM update would likely not be able to help anything.
The only way I see that it could be fixed, is for PDAwin to release an Axim X3/X3i specific version of their software. The only change that would be needed is to change the virtual keycodes used in the software. It would only take them a few minutes to make these changes. The problem would be that they would need a separate X3/X3i version every time they release a new version of PDAwin.