Getting logged off...a lot

I'm not sure why, the game runs fine, but every 10-20 minutes I just get disconnected from the server with the message "you have been logged off the system." Anyone experience this or have any suggestions? Is this normal? I have a broadband connection with very little lag so I doubt thats the issue. I'm not afk just walking/flying around and get disconnected for no reason.

I've experienced this as well, wasnt in a particulary laggy sim and ping times were lower than the usual spikes of 15,000 i've been seeing in pings to some sims and normal replys of 170, the sim didnt crash as the people who were there with me remained in the sim.

If this happens consistently after a certain period of time (like a few minutes), it's likely there's other software on your computer (firewall or internet security software) that's disconnecting Second Life.

Might not be the cause, but it's worth looking into.
http://secondlife.com/tiki/tiki-index.php?page=TechConfigFirewall