IP Extender question 

Just FYI, I've managed to solve my problem, and the same (or similar) solution may work for you.  My extender had an IP on the wrong subnet (192.168.0.123, when all my other devices were on the 192.168.1.* subnet), so I regained access by factory resetting and changing the static IP to 192.168.1.123.  Since you can't get on even after a factory reset, you could try modifyin your router DHCP settings so that the subnet it's assigning everything to includes the static IP you assigned for the extender (and if that still doesn't work, the factory default).  Assuming the subnet mask is 255.255.255.0, then this just means the first 3 sections of the IP need to be the same.