Interesting Vista problem (but solved):

We run 50-75 clients (varies day to day) off 2 Belkin N1 Vision routers.
Today all Vista machines showed only limited connectivity even with 5 bars
signal strength yet all XP machines connected normally even with only 1 bar.
The solution was a 45-second power off reboot of both modems and routers.
Any ideas why 15 or so various Vista machines would not successfully
connect? Vista used to do wifi great.