Icecast - Aug 2004 - Data wont transfer over local network, works through inet.

Hi, i've recently come into a really strange problem with connecting to my
icecast server.
The setup i have is a pretty typical linux machine using ipmasq to let a
local network onto the inet.
The icecast server resides on on the linux machine. icecast version is
1.3.10

Everything has always worked great until recently. Now, for some reason the
local lan machines can connect to the server, but always get kicked after
~28s with 0 bytes transfered.