Multiple Connection issue

My roomate and I share an internet connection. It's a Bellsouth DSL connection. Now I know bandwidth here isn't the issue, because my roomate has played MMORPG's like Evercrack (and Evercrack 2) and even WoW while I've been puttering around on SL. However my roomate recently wanted to see what the big deal was... and after a week or so he's gotten hooke dhimself.

The problem: We both cannot run simultaneous connections to Second Life. Oft times if we both are online, one of us will register the other as being offline (even tho they are online). Furthermore, after a period of time (It varies from 5 minutes to 20 minutes) we both simultaneously loose connection. No greyed out screen however, the computers literally stop talking to SL it seems, tho somehow they THINK they are still connected. Now this latter problem I've had when the modem or service took a minor hiccup, so that's not something I am concerned with. But the fact that both of our computers cannot connect to SL at the same time DOES bother me.

Can anyone offer a tweak to solve this problem (We've reduced all our loading to the minimums), or at least explain what is going on so I have some idea what the issue may be? Thank you for your time and attention.

- Polecat