I have one of the G sims that works fine in my 600. When I put it into the 650, it says it cannot be used. At the Cingular store, I tried one of the A sims and it didn't work either. The customer service guy thought maybe the fix for the treo corrupting sim data might work and I finally (thanks to this group!) got it installed (had a tablet PC and the palm desktop CD wouldn't install).

Does anyone know if the SIM has to be in the Treo when you install the updater onto it for it to fix the SIM? It doesn't seem like the SIM is currently corrupt because my voice mail phone number is still good (on the 600).