Had the same problem here :( but now updated
using PC companion it says PC companion was not able to connect to the phone. Please disconnect and connect again.
Everytime I put my phone in Media Transfer mode its not connected. I have rooted (and now unrooted & unfrozen the apps that I frozen using bloat freezer) my phone and not touched the boot loader, I will have a look for seus and try that
using windows 7 32bit
Installed SEUS and when it asked to run after install unticked it. I then found the icon and right clicked on "Update Service" & selected Run as administrator. I then followed the on screen instructions (I waited a minute before turning it back on again) and it said they is an update waiting. It has now gone through the update process and "The installation was completed successfully"
Hope this helps anybody else having problems
PS taking to ages to boot since the update has gone on ....
Now just need root for this