Can't find any CAB files on the device so I might try the hard reset. What state is the phone left in after the reset - as it came in the box? I don't want to end up losing even more Orange customisations like the data accounts, etc!
OK, I was brave a did a hard reset. It took *ages* to boot back up again afterwards - getting on for two minutes and I was really worried. However, the Home screen finally appeared and it is back in its "out-of-the-box" state. All the Orange customisations, data accounts, contacts are there. A simple synchronisation with ActiveSync and everything's back to normal
The only CAB I could find (using the file explorer application on the SD card) was that orange_uk.cab. It didn't find any other .cabs. I guess the reason the SPV took so long to reboot after the erase was that it was installing that CAB.