Ok, it seems like it was q2admin. I've removed it and had a good 6 player session last night for about 3 hours with no kicking.
I'm not playing a mod, just standard Quake 2. I thought i'd get that all working properly and then start doing some mods. Just gotta sort out map/timelimit/fraglimit voting and i think my server is finalised!
I'm not much of a programmer so i wouldn't know what to do with that clanwos vote engine, and i'm using a windows machine as the server