or I am wrong?
perhaps somebody have such to have a look inside? :)
I sent an email to Seidio to ask. They confirmed that their product does use an extra cable plugged into the headphone socket on top, and that this is because there is no audio available in the docking connector.
With the current version of firmware on the axim, if you ground either pin 5 or 6, you enable +3.3v on pin 7 with a limit of 100mA. This is to power external keyboards and serial converters.