The behaviour described below has been confirmed on OOo 1.1.0 on WinXP, Win2K
and Win98 (See http://www.oooforum.org/forum/viewtopic.php?t=6563). I don't have
the facilities/time to test on other platforms at the moment, but it seems it
may be a general issue across all platforms.

This may also be related to Issue 19863???

Steps to recreate:
1 - Open a new OOo text document
2 - Create new table (Insert\Table) - (2 rows, 2 columns is fine) (Selecting
borders and headings doesn't have any influence, but its easier to see what's
going on if you do select borders)
3 - Type some text in each cell (this isn't a prerequisite, but makes it easier
to see what is going on)
4 - Now select the entire table, right click and select Table...
5 - Under the borders tab, change Spacing to contents settings as follows:
5.1 - Make sure 'synchronize' is selected.
5.2 - Change the spacing to something like 0.1 cm  by changing one of the four
values (the others should change accordingly automatically)
5.3 - Unselect 'synchronize'
5.4 - Change the settings for top and bottom to zero.
5.5 - Click OK (You can choose to select synchronize again or not, it doesn't
make a difference.)
6 - Select the table again and, USING THE BUTTON on the toolbar change the
border in any way.

RESULT: The top and bottom spacing of each cell is changed when the border
changes. If you select the table again and go and look at the Spacing to
contents settings these have changed. This behaviour only occurs if the borders
are changed using the button on the menu, not when going through the menu and
changing the borders in the table properties dialog.

The expectation would be that the behaviour associated with the button on the
toolbar should be the same as the behaviour when changing the border through the
table properties dialog.

Cheers

Anton