Difficulty flashing RT-N66U.

I've recently purchased an Asus RT-N66U to replace my RT-N16 which has been spontaneously rebooting for a while.
Unfortunately I'm having difficulty flashing the N66U to TomatoUSB based firmware.
I have tried the following versions, all flashing through the Asus recovery tool:
tomato-K26USB-NVRAM64K-1.28.0501.3MIPSR2Toastman-RT-N-VLAN-VPN-NOCAT
tomato-K26USB-1.28.0502.1MIPSR2Toastman-RT-N-VLAN-VPN-NOCAT
tomato-K26USB-1.28.RT-N5x-MIPSR2-108-AIO-64K (Shibby)

None of these builds work. After...

Difficulty flashing RT-N66U.