Mine is still not working, and I phoned on 08003584828 and my flabber was gasted (as the old saying goes) because I got through to a human in 3 seconds!
He said they are still having issues. Apparently several servers crashed including business servers (hence 333 message recently I presume). Most of tehse have been fixed but they still cant get the Homesignal server working.
He said they are still having issues and are reluctant to give a deadline, saying they had failed to meet an internal deadline for yesterday. However, he indicated they thought it would be fixed within 24-48 hours.
He told me if the box light is flashing yellow, it is trying to connect to a server, and there will be no need to reboot/rest box etc. - it should just connect. If box light is a steady red, you probably have to reboot/reset box.
On at least one website, allegedly somebody from 3 claimed problem was fixed - this is definitely not the case.
Anyway, the guy I spoke to made a £5 credit (other apparently have been credited £10) to towards my next bill!