I am always amazed by your prompt responses. I don't respond so fast in my day job !! I'm sure DXKeep er is not your day job!
In response to your answer .. I am lazy, so when I click upload to Clublog that's the end of it. I do not change QSO's on clublog because I have neither the time or the inclination to do so - DXKeeper is my "bible" and I do not need to change a QSO there because my CW is faultless - it's the others! No this is a mystery to me because the QSO was accurately logged - mode - time - etc. (the usual errors) so even if the QSO did not get uploaded the first time, I am clicking upload to clublog maybe once or twice a day and eventually it should have gone through or been flagged as dupe. As you suggest I will pass this thread of conversation to Clublog.