Issues with Stingray Xoom and ICS update

I am trying to update my xoom to the official ICS update and its not working. I have used the files from Motodev and reverted all the way back to stock. after that i try and update and i get nothing, no updates available nothing. tried everything not dice. i can update manually flashing the updates in clockwork recovery. once back on the latest honeycomb update i do get the notification for the for the ICS update and then when it starts to install it stops and i get the question mark inside the triangle. I have no clue why i have done it several time all with the same result. can anyone give me a suggestion of what to try???

thank you in advance