Several factory resets, and Utility shows 2.10.0. I've since raised a support ticket, and they've pointed me in the direction of the Line 6 Updater software, as well as some more recent drivers.
Unfortunately I can't seem to use the PC based tools to update the unit, so I'm a bit stuck again! Running Windows 7, 64-bit (which looks like it might have some issues based on a couple of forum posts I've read) I get an error message along the lines of "Don't unplug your unit whilst it's updating". I've tried various USB ports, and have ensured the software was launched with admin rights, but no improvements.