Well whadya know I did this and sure enough up popped the March 2011 update!
I counted to 15 and (wearing headphones at the time) heard interference - I switched off my data connection & am updating my XENJK1-flashed Omnia as I type...
I have to apologise to OP for doubting
edit: Also, when my Zune said "Step 2 of 10: Downloading Update..." it got stuck at 0%. I disconnected the PPTP VPN and it finished off OK.
great solution headphones and listen interference