First, make sure that no part of the tab control touches or crosses the boundary between the body layout part and the header layout part.
If that doesn't resolve the issue, please report back. When you do so, make very clear exactly what you are doing in Layout mode and exactly what you are doing in browse mode. "Put stuff" doesn't really tell us much as that "stuff" could be fields, layout text, buttons or.... added in layout mode or it could be text entered/selected in fields while in browse mode.
Thanks for responding, and unfortunately, that has not done anything (the tab control isn't near the header :(). Rather than just try to describe it to you guys, it'd probably just be best to show you a picture.
General tab selected in layout mode: http://img849.imageshack.us/i/screenshot20110315at556.png/
Payment tab selected in layout mode: http://img12.imageshack.us/i/screenshot20110315at556.png/
General tab selected in Browse mode: http://img714.imageshack.us/i/screenshot20110315at556.png/
In browse mode, just like in layout mode, when I click the payment tab...the fields I had moved back to the general tab do not "disappear." They remain visible. I don't know what I did wrong...I followed the tutorial, moved all of my fields over to the far right (past the dotted vertical border line) to make the tab control. I try to move them back and that's what I get.
The only dotted vertical line that I see in your screen shots is the line that marks the edge of the printable area and this has nothing to do with the borders of the tab control. When you click the tab control while in layout mode, you should see small black squares appear at the corners of the tabl control. In order for an object to be contained by a tab in the control, you must first select the tab, then position the object inside these squares.
You can confirm that an object is part of a tab control by entering layout mode and dragging the tab control a small distance. If the object is contained within the control, it will move with it. If it is not, it will not move.
Thank you, sir. You are a life saver. What the missing manual neglected to mention was having to expand the tab control to make the space for the fields. Everything works now! :)