After initial good news of getting permission to travel it was a different matter on arrival in BOS.
Usual questions at immigration, fingerprints etc... then excuse me Sir just one more step and you are clear to enter the USA please follow my colleague to Secondary Immigration. Went through all the usual questions and answers again except he asked me if I had ever applied for diplomatic immunity in the USA - no I said, yes you have he said, no I said, yes you have he said it is on your ESTA documentation.
After a LOT of further questioning during which I struggled to bite my tongue, due to the line of questioning in front of all around, I was let in.
I now know why my original ESTA application was refused. I waited 10 days and reapplied and was accepted, I do not believe the system removed (or wanted to remove) my error on the first application.
All my fault I know but the system could surely be made more user friendly. Especially so as if you make a mistake and get the Homeland Security guard who just got ditched by his wife it may cause a lot of unecessary grief.
I repeat my original advice - check, check and check again before submitting your application.