Spend quite sometime entering in all these PTT numbers of my coworkers. The next time I go to send a PTT, the address book does not have them. I didn't think much about it. When one of them would PTT me, I would just copy and paste the number in the PTT fiield of the addr book. Again, later like maybe next day they are gone again. Any ideas???

I had this problem when I upgraded a 7520. And going back I realized that they changed the name of the PTT field in the two OS's and it didn't seem to port over. Did you upgrade this phone anytime recently?