MN-700 drops network & internet every 1 -2 hours

Hi,
My MN-700 base station is setup with 4 wired connections
and 2 wireless connections. The internet hookup is to a
DSL 1000 modem. All PCs are running Windows 2000. The
peer to peer network and the internet will completely drop
every 1 - 2 hours and then I have to reset the base
station (power off and power up the MN-700). Then it
works fine for another hour or two and then all
connections are lost. Lights are all green, but no
activity. Firmware is up-to-date on the base station.
Any ideas??
Thanks,
Rick