The PalmOne Tungsten T5 device is also the first device to ship using the PalmSource standard API for 5-way navigation. This API is very close to what shipped on the Treo 600. The rocker key characters are the same, the use of 'fnav' resources is the same, and the Treo APIs that started with "Frm" are the same. However, in finishing work on this API, some of the functions that originally were Handspring-only were moved into the PalmSource feature set. This means that they now have standard trap numbers, rather than being working off the licensee trap dispatcher.
A solution for this problem is on the way. The next version of the Palm OS 68K API SDK will include an updated glue library. The new glue functions will call the right system trap on the Treo 600, and use the new trap number on newer devices. This SDK will be shipping with Palm OS Developer Suite 1.1, and we will also make it available for CodeWarrior users shortly after PODS 1.1 is released. If you have seeding access, you can already get the new headers and the glue library update as part of the PODS 1.1 tech preview release, although not in final form.