Default "The key data...."

Trying to upgrade to ICS using the official update package from the Software Upgrade screen, I keep getting the message "The key data cannot be backed up. Thus, the upgrade cannot proceed."

When I use the powerup method pressing the volume control up/down it just says "Update failed" and stops on the first step.

I am using a U8800-51, currently running 2.3.5 and Stallion-51_ics with 404020 baseband.

I suspect it is something to do with partition sizes but not sure.

Any ideas guys?
Asus Transformer TF300T
ROM: CROMBi-kk 20140811
Kernel: _thatV10
Android Runtime / F2FS

Kindle Fire HD
ROM: CyanogenMod 11-20140811-NIGHTLY-tate
Kernel: 3.0.72+
Android Runtime / F2FS

Asus Transformer TF700T - Stock

Huawei U8800-51
ROM: MIUI multilingual ForEver 2.3.7

Samsung Galaxy S4 Mini Duo GT-I9192 - Rooted - stock with bloat removed

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