ReadyNAS Duo Upgrade to 2TB Hard Drives

so, two backups later (due to paranoia) I pop a fresh 2TB disk all on it's own into the readynas duo when off.
Hold down the reset button and push power button, release reset after 30 seconds and LED flashes.
Access through raidar and select standard xraid2
various lound fan noises and about an hour 1.5 hours later radar indicates that system is up
access through the web portal to find readynas null on the homescreen and no menu
A few google searches later http://www.readynas.com/forum/viewtopic.php?f=65&t=28107&view=previous I do a os install
further 30 minutes later (just to be safe) same readynas null issue.

I can see the nas on the network and access the media and backup shares - although I've not tried writing to them yet.

Any thoughts from anyone how to get my admin menu back?

Do i need to wait even longer as it is a 2tb drive?

Kind regards

Ben