In OOo Writer one can define a page background image/colour by entering the
Format->Page menu and then setting the option Background->As Graphic, then
Browse... and selecting a file.  This is a good option e.g. when a watermark or
page frame (for decoration) is desired.  Similarly, this works for page
background colours.  However, there is a problem: The background image/colour
really is a text area background, not a page background.  It does not extend
into the margin (as set in Format->Page...->Page->Margins).  This most probably
was not intended.  Watermarks, page colours, and most importantly frames/border
decorations need to be defined on the page, not within the text area only. 
Otherwise a frame will not frame the text but drawn over/under it.

These are temporary workarounds for the problem in the page setup if someone
wishes to have a page background, e.g. a decorative frame around the text:

 1 - set page margins to 0pt, then enable drawing of Format->Page...->Borders,
set Spacing to Contents to the previous values of Margins.  Problem: the border
will be drawn with a colour, not transparently.  This is a problem for some
printers.

 2 - insert the background image via Insert->Picture, anchor it to the page and
have it fill out the whole page area.  Set option Wrap->Wrap Through to have
text inside the image.  Problem: One cannot select text within the page via
mouse clicks anymore :-(  Any mouse click (left button) will select the image,
instead of placing the text cursor.

Maybe the most backward-compatible type of fix would be to make this an option?
 However, the default for a page background should be to extend to the whole page...