My thanks to all who have responded with possible causes, questions, etc. Lotsa knowledge here, and that's why I asked the question.
It seems unlikely that it's a key malfunction matter, as it ONLY occurs with a W5Axx call entry ... not with a 5Axx or any combination of letters surrounding the 5 ... and not with any other number/letter combination. It only happens with W5A. Remember, I've now entered about 15K QSO's and this is the only problem I've seen. I haven't connected another keyboard ... I will. The one in use is a Logitec cordless. Related to a key logger? I doubt it, as the computer in question is almost never "on line", and is used only for DX4WIN. The computer's OS is XP and it has Norton 2007, Spybot and Ad-Aware software that's updated and run once a week ... about the only time the machine's "on line". The only other "on line" activity is to visit the Elecraft site for updates to my K3. The laptop that works OK has the same OS and software ... they are almost mirror images of each other. I don't view the program as "crashed" as one respondent termed it. The "A" keystroke just instantly returns me to the open desktop and then I can restart he program "normally" via the DX4WIN icon. All data is then current through the last auto back-up no more than one minute prior to the closure. Thank you all for your efforts ... I'll let you know what/if I find. 73! Ken Kop - K0PP [EMAIL PROTECTED] or [EMAIL PROTECTED]