form movement

Access03: kind of difficult to explain

form has a tab subform about mid height in the details area
(mid height meaning about middle high in a typical screen - or it otherwords
the tab subform is not up at top of the details section)

when one selects a tab - the focus is going to the first control of its
section - which is ok; but the entire form slides up so that this control is
the top of the details section - - and thus one can not see the data that was
above the tabs unless you manually scroll down.

I've experimented by trying to force the focus to a control just above the
tabs in the tab OnClick - but the focus is not going there. Have also
attempted in the subform open event and that didn't work either....

how does one stop the form movement?

tia