Hi Fred,
no, nothing to do with socket closes or screen locks (anyway, the screen lock should only freeze the screen refresh, not the other activities under the hood). If you move the cursor over the program window, without clicking and focusing it, the program suddenly starts to receive messages, and stops if you move it out: it is as there was a lack of generation of internal periodical refresh events.
And, in any case, if you create the app using version 6.x of LC, the problem disappears.
And no, I'm not a beginner, I just forgot my former user name and I had to register myself again
Anyway, thanks for your interest.
Mario