yeah. the same thing happens to me and another girl I know. I don't know what the problem is. I've sent in a complaint. It seems to kick me off, but doesn't inform me that i'm no longer showing up on any of my buddies IM lists. I would IM my friends and no response. Then I realized I was cut off.
I use the Quick Buddy version as well. It sucks too, but at least I'm not getting kicked off. And my friends in the office tell me I'm logged on and show up on their lists, so I know it's working.