Just out of curiosity, did you reset the configuration to default after flashing the firmware?
I usually make it a habit to flash, reset to default, reboot and then manually reconfigure. It's a pain if you have a lot of rules set, but I have had no problems with my HW: A2, FW: 1.10 router.
Intel Wireless-N client
Broadcom Wireless-G client
D-Link Wireless-N client (now working)
Vonage phone adapter, wired