I'm not sure what else it could be. The only other thing that I changed was to disable DHCP in the access point. Other than that it ran perfectly first time. I did find there was a new flash upgrade for it which I applied. It gave the access points a lot more features but mainly for people that wanted to hang it directly onto a cable or ADSL modem for NAT sharing etc.
I hope you can get it running soon, you should be very pleased with the performance, I know I am.
All the best