You should post a reply to say you solved the old problem, and with the new problem if necessary. I wasn't sure what you meant until I scrolled up and found "Any ideas?"

Anyway, if you're using wine, the registry is stored in the files "user.reg" and "system.reg" in your wine directory (~/.wine/ probably). If you run JJ2 it will create the registry keys for you, and you can edit the values by editing those files. Most of the keys for JJ2 are in user.reg; the only one in system.reg is the list servers key. All the keys should be created when you run JJ2, but some of the values may not be unless you use them (like multiplayer names/colors).

To add the list server values, open system.reg and find the line that starts with:

There will be a number at the end, which I think is the timestamp for last modification, but you don't need to change it unless you really want to. Underneath that line, add these two lines:

Save the file and try to play online.