It's possible to drag-and-drop the left margin so that it meets the right margin and even overlaps with the right margin. This causes an inconsistency with the values and limitations in the page format dialog and just when the margins meet, all text is hidden (but not when overlapping).

Steps to reproduce:
1) Create a document with some text, images and other objects
2) For one line of text, move left indentation marker (the "hour glass" on the top ruler) 1 cm to the left
3) For the same line, move the right indentation marker (the "triangle" on the top ruler) 1 cm to the right
4) Drag-and-drop to left margin all the way over so it precisely meets the right margin.

Expected Result:
- The left margin should not be able to go within 0.2" of the right margin (the limitation from the page format dialog).

Actual Result:
- The left margin meets the right margin
- All text is hidden (not just the selected line)
- All objects just visible as a thin line

5) Open the "Format -> Page" dialog and go to the "Page" tab

Expected Result:
- The sum of the left margin and the right margin should equal the page width

Actual Result:
- The left margin and the right margin together is 0.2" smaller than the page width.

6) Drag-and-drop the left margin further to the right so that it overlaps the right margin

Expected Result:
- The left margin should not be able to go within 0.2" of the right margin.

Actual Result:
- The margins overlap
- All text and objects are visible again

Notes:
- See the attached video for demonstration of this bug
- MS Word does not seem to have this behavior

Platform:
Libre Office: LibreOffice 3.3.4, OOO330m19 (Build:401), tag libreoffice-3.3.3.1, Ubuntu package 1:3.3.4-0ubuntu1
Ubuntu 11.04: 2.6.38-13-generic #52-Ubuntu SMP x86_64 x86_64 x86_64 GNU/Linux