There are reasons for it not working online.
Linux uses slightly different versions of Network Protocols which I believe the Listserver isn't meant to read.
Unless you can completely emulate your connection it won't work.
Besides, I found that loading Graal Client in any way on Linux just causes the WINE Server to freeze, or the X Windowing system.
Precisely why I use it on Windows.
But the RC seems to have no problems with Linux at all.