Download the file at :
http://www.megaupload.com/?d=MJIICQP7
Unpack it and copy files to the root of your memorycard and follow the instructions.
Use the keygen the were release for the TomTom 6 on PalmOS.
Copy the small Guam map to the card and activate it through the keygen. Now you are up and running and install for example a scandinavian MAP.
Great news eh? I am running Tomtom6 now on my P990i with the scandinavia map !