gsm modem sms problem

[susuke]

I want to send sms under a sw, that was written in borland c++ builder 5. I use Varian Async 32 package (TVaComm component).
There is no problem sending sms, but the text of the sms is not correct. There's some 'alien' characters at the beginning of the sms when it is received by the phone and some characters lost.

I tried to reset the modem, purge the read and write buffer but there's no change. (The modem is a nokia6310).

What can be the problem?

Thanks for any help.