Have at last pinned down the problem - the Dynamis hand controller lost its brains for a while, but after a few attempts at re-setting it eventually corrected itself, so all's well that ends well.

Many thanks to Jim Banner, Poliss and NarrowMinded for your input and encouragement.

Best regards

Winston

1. The loco is a Thomas made by Hornby
2. The decoder is an R8249 4 function
3. It was installed by my local model shop
4. Not tried prior to installation
5. ?
6. I am using the Bachman Dynamis system
7. It ran O.K in the shop before I brought it home (they were using Hornby DCC Controller)
8. All other loco's run very well, no problems.
9. No it only ran forwards
10. Yes I did reset it and no it still only runs forwards
11. No, but I did return it and there comment was "reverse was switched off" but the problem still persists

I have a Thomas Loco which after programming refuses to reverse.  Has anybody got any ideas as how I can resolve this?