Have a client with ip500 4.1(15) with a mutitech faxfinder 2 port fax server. the analog ports on the Phone 8 Module keep going to a busy after one call into the faxfinder. Power cycle the IP500 and the port is ok then it will take one call and then all calls after that will get a busy. HELP!!! Don't know how to pursue this and find the issue.