GSM modem returns rubbish symbols no matter the command sent

Good day.

I have a WAVECOM 16 port GSM modem.

I have been able to connect to the device through a serial connection using PUTTY.

No matter what command I send I get back random rubbish responses.

Here is some information from the log file:

=~=~=~=~=~=~=~=~=~=~=~= PuTTY log 2013.11.08 09:58:54 =~=~=~=~=~=~=~=~=~=~=~=
AT
û[¯AT+CSMS=1
{ïßïïoïïïATDT27741481203
Ûï¿ïÿk¿ïïýÛïï¯AT&V
[ïï¯ÿAT+CSQ
{ïoﯭÿ
ëATI
{ï¯ý
ë+++
{ï¿ïÿCN=1
k¯{ï&FN = =1
{ïßï
ûAT
ûo¯AT
{­ÿAT
â–’[â–’AT+CSMS=1
{â–’â–’â–’â–’oâ–’â–’â–’ATDT27741481203
â–’â–’â–’â–’kâ–’â–’â–’â–’â–’â–’â–’AT&V
[â–’â–’â–’AT+CSQ
{▒oﯭ▒
â–’ATI
{â–’â–’
â–’+++
{â–’â–’â–’CN=1
kâ–’{â–’&FN=1
â–’â–’â–’
â–’AT
â–’oâ–’AT
{â–’â–’

I am using windows 7 64 bit.

If anyone has any ideas what may be wrong please let me know.

Many thanks

Regards

Ben