What's using my modem?

have fax software (Ventafax) which is giving an error message "Modem

occupied by another application". It would seem that something is scanning

the modem every 20 seconds. In normal operation it's possible to hear (via

the telephone) the modem dialling out but nothing is heard. I'm not aware

of any changes that should have this effect. How do I find out what

software may be causing this? I can't see anything obvious either in the

Services or StartUp of System Configuration Utility.

Thanks.

Bill Ridgeway