Word 2003: Including indent in table style

I'm using Word 2003, and have a problem where even if I manually set
an indent on a table, it will at some point move back to the default
position. I want to make sure that the indent is set permanently.

I've tried editing the style of the table, and setting the value for
"Indent from Left" in Format==Table Properties=Table to the required
value. However, this has no effect. Only directly setting this value
for individual tables seems to work. Even then, they move.

Any advice appreciated.

P.