Please help ... unnecessary text messages

Archived from groups: alt.cellular.cingular (More info?)

I bought an unlocked Sony Ericsson T610 and put my cingular SIM card in it.
It works but after every call I receive or make, I get a vibrating text
alert. It says "unknown" in the message and I've called Cingular to make
sure they won't charge me for text msgs. But it is annoying.

Has anybody seen this? I have fiddled with all the phone settings and cannot
turn it off.

Please help ....

Sandra B.