different behaviour from editor and standalone player

I'm having some issues with network connections.

I'm using a custom UDP socket library to connect to a server. when running my scene in the editor everything is fine - i can send messages and receive data back from the server.

When i build as a standlone app, though it all breaks down. In both windows and osx messages are sent once every few seconds (instead of several times each second) and i get no data back from the server at all.

this is clearly not server-related as it all works well in the editor. I'm just wondering if i'm doing something stoopid in my UDP socket handling.

Is there anything obvious i should be looking for? Any known issues? anyone seen this sort of thing before?

T