Checking the programs I found one that had a "select" (under
commitment) and it may have returned without releasing the record. I
added "with NC" to the select, and since then I had no more records
locked, but because the problem appeared very seldom, I am not sure
if that was the solution.
Is it possible that the "select" was locking the records? I have
"commit" or "rollback" on every update, but the "select" was alone.