I believe i've heard that you do not get this if you have a Security Token active.
However, for a more immediate fix, this happens everytime you're logging in from another location, or rather, from a diffirent IP adress. My bet is that you do not have a static IP adress, which is causing the problem everytime it resets. You could try setting a fixed IP adress instead of an automatically allocated one in your LAN's properties.
Or it could just be a problem with your ISP or modem resetting itself a lot. In that case, i have no idea.