That's odd, definitely something else then. Some of the earlier versions of RB ran slowly if you had "Share Data" selected when you weren't connected to the internet, but this has been long fixed. You have to look at your PC here I think. If it was an issue, it would happen for everybody. Anti-virus software, programs running in the background sucking up processing power, even a poor antenna connection?
When you say you have to log out, do you mean that you restart the PC, or just restart RB?
Sorry, I keep editing this reply - do you loose Network traffic and live traffic at the same time?