fsockopen works on other systems, doesn't work here - why?

[luxfx]

I'm trying to debug this with a client, and am running out of options. Does anyone have any other suggestions?

Part of an application I have released uses fsockopen to open a port at 14242 on a client's server, and sends the message to the client's personal computer. This literally works fine on hundreds of other systems, but this one system still gives problems. This one client doesn't receive the message, and the fsockopen command returns error: "Connection refused (61)"

specs:
-Client has Windows XP system
-Server has FreeBSD4.4 with PHP version 4.2.3 on Apache 1.3.22
-Server host has claimed there are not ports being blocked, and checked port 14242 specifically.
-The XP system has ZoneAlarm on it, but specifically gave server rights to this application. We've also tested it with ZoneAlarm completely shut down.
-The client's IP address is being reported correctly, so it is being sent to the right place.

Are there any other avenues which I might check? I'm running out of ideas fast, and I really don't want to have to tell the user "it just isn't working" after we've gone through more than a dozen correspondances trying to fix this.

thanks
-david woods

[morphy_6deex]

the connection refused of yr web server is the connection with client's server and not with the client's pc... is it? so, u have to check the socket among web server & client's server... if client's server and client's pc r the same machine (the xp one) could be the xp native firewall? has that machine a service running on 14242 ? can u ping client's server on that port ?

can u be more detailed?