I recently rooted my Vodafone (UK) HTC Desire after the bloated 2.1 release from Vodafone but never got around to flashing a custom rom (after problems with the clockwork recovery Amoled or SLCD). I know wish to install the clean(er) 2.2 official Vodfone OTA release but I'm having trouble. When I download OTA the phone restarts and hangs at a screen with a triangle and explanation mark. I can then get to the recovery screen where I se the error - failed, un-verified signature. Can anyone shed any light on what I need to do to install the Vodfone release, do I need to un-root my phone first? Thanks in advance!