I've had to be careful of this too. I use RTM and had a saved search that showed me "due this week". The problem was that I wasn't getting to my other context lists. I only thought about what was due on that list. I've found that it actually helped me to get rid of the search and just concentrate on where I am. When at work, it's @work and @computer. When at home, it's @home or @computer. When I get in the car, there's the @errands list. For me, it was more a matter of focus than a system problem.