[SD-User] ARRL contest difficulty

[PETER CLEALL]

Have recently returned to transmitting after a gap of 40 yrs.

I have been playing with SD in a practice/training  mode for about a month .
I am impressed with what it can do.

This weekend I decided to have a go at a few qso's in the ARRL contest. I
used  SD live and worked and logged 18 stateside stations. when I came to
add number 19 AA1K  59DE I encountered a problem.
When I added the DE for Delaware the software told me that it was "not
valid".

I could not continue to add QSO's until I deleted the whole AA1K logging and
pretended that I had not wkd that one.

Can someone suggest what I am likely to have done wrong so that I can avoid
it next time.

regards
peter G8AFN