Eight months later and still no resetting issue! Just for kicks, I enabled UPnP on my SMC2804WBR router and immediately Vista caused my wireless to drop out.
I have a Vista laptop, an old Win2K laptop, and 2 WinXP desktops and with UPnP enabled, the wireless router works fine as long as the Vista laptop is not connected. Had to turn UPnP off again on my router in order to post this message. So far, I haven't seen a solution from Microsoft that works. THIS DOES!