kicked

I was just wondering how and why chatters go in and out of chat room without their knowledge... I mean sometimes in the middle of a convo and they have to log back in? Its very inconvenient at times?

Whenever I am in a room, any room, chatters come in, leave, come back, leave etc. etc. many times. When they do return they say they have not left really but seem to have been kicked out? Can anyone or an admin tell us why this happens so regularly.... It is so annoying when in the middle of a...