Hi Mouton,
Yeah, the type of problem you describe can be caused by MTU settings on routers, but in this case I'm confident that the network is OK at both ends, as the problem only occurs with FFXP3.
Your suggestion about the rollback warrants a test though, so I'll try that later when I get home. FFXP3 seems to be fine on my Win2k SP4 here at work!
Thanks for your input
UglyBunz