Do you have subforms on the tabs that are not lined up? The tabs themselves
don't move but if you have subforms on the separate tabs and the subforms are
not in the exact same position, it give the appearance of moving.
The selected tab will "move to the front". If you have multipe rows of tabs
then selecting any tab not in the front row will move that entire row of
tabs to the front row. You can use TabStyle=Buttons instead of
TabStyle=Tabs. Buttons don't move at all.