>My purpose of running such code is exactly to find why GetFldState reports a change when there was no visible change (I only opened a form and then pressed close at the upper right corner).
Then check at what position of GetFldState(-1) there is a "change", and check that specific field. If it is at the 4th. position, check the old and the new value of the 3rd. field (remember, the first byte of GetFldState(-1) indicates the deleted status).
This will only tell you whether there really was a change or not, not WHY there supposedly is a change. For the latter, you may want to put a breakpoint, when condition is true:
"2" $ GetFldState(-1).
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)