SIEMENS TC35i returns extra charcter in reply to Command in Visual Basic,Hypertermial

Hello

This is the first time I am using this forum and I have taken due care to select appropriate category but even if I have selected wrong category, please help me correct it I am really stucked with a problem of extra character in TC35i .

My issue and its explanation is given point wise :

1) Product I use is Siemens TC35i GSM Modem, Serial Interface, Single Port.

2) I have developed an Visual Basic 6 Application using MSComm Control to read incoming SMS

3) I pass the command simple "AT+CMGR" to read the SIM Card Message.

Issue I face :

The issue is face is only in few modems out of several / similar / same spec modem I use. For e.g. out of 10 Siemens TC35i modems I used, I am facing problem in 02 (two) , problem which is as under :

1) When I use the command "AT+CMGR=1" using Visual basic 6 application it gives proper reply i.e. i get is as "AT+CMGR=1" ....along with other text in 8 modems out of 10 i have.

Where as in 2 modems it misbehaves and gives extra characters in reply. The reply I get in Visual basic software from these two modem is = "RAT+CMGR=1 OK" . Problem starts here, I get "R" which is extra in the beginning of the return string , where as for the same specification modems ( 08 pieces ) it gives perfect reply as "AT+CMGR=1" , means it dont give extra "R".

Now when I try type same command in hyperterminal and enter "AT+CMGR=1", it is automatically typed as "AT+CMGR=R1" (note that i have typed AT+CMGR=1), I have never type "R1" BUT THEN ALSO in hyperterminal it is shown at "R1" , so again "R" is coming as extra.

I have tried several different computers for this 02 TC35i modems and in each computer the modems returns "RAT+CMGR=1" where as it is suppose to return "AT+CMGR=1" ....along with rest of the text.

Why I am getting this extra "R" in reply. This creates logical problem in the software as I calculate character length in return string. Moreover I use more advance commands also and in these two modems it don't give proper replies which makes my software to crash.

Can I get help in the matter ?