I'm running Squid on a FreeBSD server using basic configurations. All is well regarding my clients and their Web browsing. The problem is with my ShoreTel ShoreWare clients (VoIP app that tells my users who's calling, if they have voicemail, etc.) It must use whatever proxy setting is in IE. Squid will not allow the ShoreWare clients to connect to our ShoreWare server at (172.17.137.7)--which is on the same subnet as the proxy server. I get the following two errors in my /var/log/squid/access.log file:

1126127000.956 7 172.17.137.108 TCP_MISS/200 204 GET http://172.17.137.7:5440/CSIS/CSISISAPI.dll/? - DIRECT/172.17.137.7 text/html

1126127000.966 5 172.17.137.108 TCP_DENIED/411 1712 GET http://172.17.137.7:5440/CSIS/CSISISAPI.dll/? - NONE/- text/html

On the other end (the shortel server running Windows 2003 server with IIS the http error log has:

2008-03-05 22:34:00 172.17.137.108 1085 172.17.137.7 5440 HTTP/1.1 GET /CSIS/CSISISAPI.dll/?request?7c389076-985d-45d2-a98a-f20bc3464a5f;CCSISSvrCONN%3A%3AwaitForEvent%3B3%3B 300%3B3%3B120 - 1 Connection_Dropped CSISAppPool

2008-03-05 22:36:00 172.17.137.108 1479 172.17.137.7 5440 HTTP/1.1 GET /CSIS/CSISISAPI.dll/?request?91f0d129-f9f9-4952-9918-bb6d75366b22;CCSISSvrCONN%3A%3AwaitForEvent%3B3%3B 300%3B3%3B120 - 1 Connection_Dropped CSISAppPool

I have attempted to specifically allow the IP addresses, the entire file path, the ports in question, and altering the permissions as to allow full access to everyone and none of it has worked.
I know that the everyone full access is bad but I had to try =)
Any ideas are appreciated. Anyone else doing the same that I am (with Squid and ShoreWare)?

Thanks,
Adam