This is absolutely true.

I purchased an unlocked GSM Treo 650 from MacMall last week. It arrived and worked fine -- except that it would not receive incoming calls. It made outgoing calls just fine. All incoming calls were routed directly to my voicemail. There was one odd exception: if I was already on an outgoing call and a call came in, I would recieve the notifiation beeps, caller ID, and I could answer that call, even start a three-way conference call. So incoming calls would "work" under these circumstances, but normally they would go directly to my voicemail. (I also would not be notified of voicemail, probably because the voicemail system needs to contact my phone to do so, and incoming calls weren't making it through.)

I should say upfront that I was switching from a BlackBerry 7100 on T-Mobile. And I should add that other threads on this forum have noted this same issue with former BlackBerry owners.

Thinking that this was a network problem I called T-Mobile and spent over an hour on the phone with them, getting bounced all the way up to tier 3 support. The technician had me put the sim in my BlackBerry: incoming calls worked. He declared it was a device problem.

I then discovered the above mentioned thread here at TreoCentral describing the same problem from other former BlackBerry owners. One reader mentioned a possible fix: put the sim card into a non-Blackberry GSM phone, make a call, and the problem seems to go away when the sim is put back into the Treo.

So I tried this with the only other GSM phone I had access to, a friend's old (B/W) SideKick. My sim would recieve calls in the SideKick -- good. So I made a call on the SideKick and then put it back into my Treo. Called the Treo: NOTHING! The call went directly to voicemail again!

Now I called Palm. The technician there (where is there?) had me do a hard reset. Didn't help. He then told me to swap out the sim into another phone, see if the problem persists (I assured him I had already done this, and the problem went away). Then he wanted me to put someone else's sim into my Treo and see if that would resolve the problem. I tried that, but the only other sim I had access to was ... you guessed it ... a sim in someone else's BlackBerry. Incoming calls went directly to her voicemail.

So at this point I decided the Treo was defective and contacted MacMall for a replacement. They were out of stock but gave me an RMA number and promised to ship a new one in a week.

Realizing I hadn't really explored all the variables in my tests, I decided to purchase a brand new sim from T-Mobile. So I visited my local T-Mobile store and did that. They activated it under my existing number and told me to wait an hour of so for that to happen.

When I got home I put the new sim into the Treo. The switch had already been made and the phone was active. I made an outgoing phone call -- no problem. I then called myself on my land line. And guess what?


Multiple calls from multiple phones. IT JUST WORKS! I also receive notification of voicemail messages that get left.

So, folks, the bottom line is this: If you are a former BlackBerry user, and you've switch to a Treo and are using the sim from the BlackBerry, and you're having problems -- RUSH RIGHT OUT AND BUY A NEW SIM. It will fix these incoming call problems (and I see *lots* of reports of this issue here on TreoCentral).

The second bottom line is this: don't contact T-Mobile or Palm support. They don't have a clue about this. Both will swear up and down that it CANNOT be the fault of the sim card. But clearly it IS the sim card.

I find this to be an AMAZING story. How could both of these tech support departments be so clueless? How much money are they wasting with returned Treos, when the solution is just to put a new, non-BlackBerry "blessed" sim card into the Treo (a $20 purchase)?

I hope this helps someone who is having the same problem I did.