I'm also having problems with this ADSL router. In my case, with the DMZ and port forwarding. Port forwarding seems to work sometimes in some ports, in some not. In the cases it works, it seems to apply the settings instantly, no need to reboot. When it doesn't work... well, neither a reboot will make it work.
Also problems with the DMZ. I live in Argentina. If I put one machine into the DMZ, then that machine can only enter sites from Argentina, if I try to enter sites from other part of the world, it never access them, it goes in a constant loop of waiting. When I put that machine out from the DMZ, all works "well" again, but then I need to forward ports, which doesn't seem to work properly...
Any ideas ?
HW version: T1
Firmware: in the sticker says BCM-3.10L.TF.20090327, inside the configuration page, it says GE_1.80.