I have a weird thing here:

I have FrostWire 4.10 installed at one of the clients.
The Clients are behind a MS ISA Server 2000.

I'm using FrostWire with TCP port 6346 (default gnutella port) for incoming connections
I made a protocol rule with all necessary information and I binded this protocol rule to a server publish rule in ISA Server 2000.

But FrostWire can't make a connection:-(

The weird thing is that when I use sites to test if a custom port is open, then these sites say: Port is open, so the port is forwarded well via MS ISA Server.

And all the other P2P programs that I configured the same way (other ports ofcourse) work perfect.

Does frostWire also need other ports to function well?
Or what else can it be?
I'm out of ideas, coz the other P2P programs work fine with ISA Server and also Port forwarding test sites say that port 6346 is open.

Every idea or suggestions are welcome:-)