Many thanks forn your replies, I check all my decoders on a test rig, they are all set to address 3. I tried changing them to another address i.e. 1536 and the direction lighting works correctly. There does not appear to be a place in the Lenz system for altering the operating of function for latching. Any way the main problem has been resolved, just have to sort out why it is only address at some point
Regards
Roland