Outbound Prefix problem

Hi, We use a 9 to dial an outside line and pick up our SIP trunk, have been for around 4 years. I have been told that nothing has changed but this no longer works… our SIP carrier tells us the call is barred as they are receiving the 9 followed by the actual telephone number, which I can confirm via the Asterisk logs.

As a temp. measure we have removed the 9 so users can dial directly out without a prefix. I also had a backup route by dialling 8 to pick up test ISDN lines, that is also no longer working.

The problem is I’m not sure why it’s no longer working, I have tried several other single number prefixes and none of them work. Watching the logs Asterisk is no longer removing the prefix. However if I set the prefix to *22 it works, the *22 is removed and the telephone number is dialled… very bizarre.

Following the issue I have upgraded to FreePBX 2.11 via the Module update but it has made no difference.

Can anyone give me any pointers.
Many Thanks…