[Dx4win] Strange behaviour

[Paul GRANGER]

Hi all
I have worked SM1IRS which is a valid callsign (confirmed on Lotw)
It has a Y in the Label field, which I want to change into an N.
When I do that, I get a message saying "bad callsign", and the QSO 
appears txwice in the log . The second appearance has a Y in the label 
field....
I have tried erasing the QSO and entering it again, I get the same issue.
What is going nuts about this callsign ??

73
Paul F6EXV

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