Well the "Number unavailable" error disappeared by itself. ( Weird). So now I have had a chance to try Peter's advice to select arial first.

On the UK TiVo Image there are 5 Programme Source options:
1. Arial Only
2. Arial + Digital Cable/Digital Terrestrial
3. Arial + Analogue Cable
4. Digital Satellite + Digital Cable/Digital Terrestrial
5. Arial + Digital Satellite

I've been using option 2 on this box, but I've tried them all now without any real success. Here are the results:

1. Arial Only - not suitable for set top box use, ignored.

2. Arial + Digital Cable/Digital Terrestrial - actually this only gives one chance to select a service provider, so I selected 'Foxtel Digital - Satellite, NS' which is what I'm using. When selecting this one, the channels are still wrong, showing the old satellite lineup. In fact I just realised that each Foxtel channel shows (cab) next to it insteal of (sat). I wonder if that indicates this lineup was wrong from the start. Tried several other service
providers, including Digital FTA (wrong lineup for what I need, and no choice to select an additional Foxtel lineup) Foxtel Digital Cable (same wrong lineup as Satellite) Austar Digital Satellite (still the same old/wrong Foxtel lineup) and just plain non digital Foxtel (completely wrong channel numbers).

3. Arial + Analogue Cable - exactly the same as option 2

4. Digital Satellite + Digital Cable/Digital Terrestrial - I get the message 'No service providers were found in your Postal Code.'

5. Arial + Digital Satellite - exactly the same as option 4, i.e. 'No service providers were found in your Postal Code.'

Now I seem to remember having option 4 working previously on my boxes, and believe this was the option that previously allowed both FTA and Foxtel to be set up as Peter suggests. Maybe the problem is now this option doesn't find any service providers for some reason?

So to summarise: the old 'Foxtel Digital - Satellite, NS' service seems to select the wrong lineup (NS12015 instead of NS02015). When I try to change to another Programme Source that theoretically should allow the correct lineup, it instead fails to find any Service Providers (and I know this option used to work a few years ago).

Any suggestions greatly appreciated!