[Steve in Pudsey]

I don't see why they wouldn't have rehearsed the opt outs, after all the regions weren't doing them into TVam. However of course they wouldn't have been able to test the last bit as they couldn't put them to air until the new year.

It would have been the first time they could do the whole thing end to end for the reasons you mention, but I guess it was a unique opportunity as the ITV networking moved from BT to NTL, they could put the remotely controlled switching kit (that let GMTV's gallery put the regional studios on air) on the new outgoing NTL circuit (that wasn't being fed to transmitters yet) and test it to their heart's content while normal output continued on the old BT circuit to the transmitters.