Vista - Losing Wireless Internet Connection

Computer runs 24/7 using Vista Ultimate and every 6 (occasionally 7) days
the wireless internet connection dies. My VOIP phone and a Win XP computer
that are hard wired to the router continue to connect to the internet. The
icon in the sys tray shows that I still am connected both local and internet
with excellent signal strength as does the network and sharing center. The
diagnose and repair function is unable to correct the problem and the only
solution so far is to reboot the computer (rebooting the router does not fix
it). I've replaced the router with a new Linksys WRT300N router and
WUSB300N adaptor with latest Linksys firmware and adaptor driver. This is
the only issue I have with Vista and is more an irritant than anything since
a reboot corrects the situation. I can't decipher anything in the event
viewer that might be related (actually I can't decipher anything in the
event viewer). It's been happening for a long time now and I can't relate
it to anything that might have been installed or updated.