Hello,
I have same problem with this device, working fine for few days keeping connection fine with my router Linksys WAG320N and then losing conection and security LED start blinking on Buffalo.
I have latest firmware I think Ver.1.52 (R1.04/B1.02) ?
I tried set diffrent options with connection with set Stacic IP in Buffalo or DHCP nothing help, also with Linksys set to "DHCP Reservation" IP from Buffalo still no luck same situation still losing connection after few days.
When this happen I tried connect again from my Linksys, but Buffalo is not visible? from Linksys.
My only solution is unplug my router Linksys and plug in to wall socket again and then connection is again established fine with Buffalo, security LED immediately? stop blinkig.
Please someone from Buffalo support can answer how to fix that :(