Linksys BEFSR41 and Vista

I currently have my internet connection running through Linksys BEFSR41 v4.1
router to 3 desktop PC's (two with Windows XP Home Edition, and one with
Windows Vista Ultimate x64) and an Xbox 360. I'd had no problems at all
before upgrading to Vista, but it seems that immediately after upgrading, my
internet will disconnect every 15 minutes to half an hour (this occurs to all
machines on the network, not just the Vista PC). I have not changed any
settings in the router config from when I had Windows XP (Professional x64)
still installed on the PC currently running Vista. The router is updated
with the latest firmware from Linksys, and when I plug my modem directly into
my PC, there is no problem at all, leading me to believe it is the router
causing the problem. I was wondering if there were any fixes to this, either
permanent or temporary (until I get a new router). If there is any other
information I can give that would help, please let me know. Thanks.