After no success with harmony email support ( never had any reply from my 2nd email), i rang support. I had to quote my incident number which i was given in their 1st email response then they knew straight away what i was calling about.
They talked me through updating the firmware - again

then still not solving the problem told me to ring back later in the afternoon

and they would put me through to `level 2` support - in Canada i was told.
Rang again later and asked for level 2 support, spoke to a very nice chap who again talked me through updating the firmware.
He then decided that the remote may be FAULTY.
He said he would contact the warrenty department for a replacement but was told it could take days to hear from them.
I decided to return the remote to where i purchased it from & got a replacement.
I have not tried the new one yet. I am about to unpack it.
I would suggest if you have the same problems, return it straight away if possible as faulty.
I will let you know if the new 785 works ok.