Overlapping forms
can be influenced by the window sizes of other forms; e.g. you might get a form behaving as you wish, open some other form then maximize it in code (or just use the control box icons in the form window header) and close it. That perfect form may very well take on the size characteristic of the last closed window and become maximized itself. Here's a method that I wrote down a long time ago ( I think it's from Albert. D. Kallal but I'm not sure)
In design view -
autocenter: yes; border: sizable; autoresize: no
switch to form view
size the window, save, switch to design view
border: thin; min-max: none
form view - save
I can't recall having an issue after that. One thing that might have to be considered sometimes is the area reserved for vertical scroll bars. If not set to "none" (or is it no?) when not needed, sometimes that area remains as background when the scroll bar is not visible, even if it's not a continuous form.
(which is different than overlapping)
Not sure but I think the term overlapping here was only used to refer to the db option of having tabbed forms or not.