Its a PITA isnt it?
Ive now got TomTom Navigator 3 running quite nicely on my Orange M2000 (Windows Mobile PocketPC).
Everything works very well (incl the phone) and the Otterbox 1900 though a bit bulky, serves as an excellent case to hold it all in.
I meant it as a play/test thing but its working so well I may well keep it for the duration. Also, Navigator 3 has some pretty good features and is much more useable on a bike (ie avoid an area, specific road(s), saveable itineries etc).
Mike