The patch, which is available to download now, fixes many bugs on the network side of the game, including setting up games and the user interface. Some new features have also been added. You can now chat in-between turns and for those with port forwarding issues pug & play support for routers is now available. The problems with the "never-ending rope hooking" bug have also been resolved.
To download the update and for more information visit the Worms 4: Mayhem downloads page on the Codemasters website.