see attached document. should be in page break preview; try to drag border 
between pages 2 & 3 or lower printing  range border.
if a merged cell crosses several pages, it is possible to print it that way, but 
it is not possible to rearrange page breaks (oo.org insists on changing page 
borders only across full cells, but even then it fails - try clicking on the 
border between pages 2 & 3 - oo.org moves first page border there and it becomes 
unselectable/unmovable)
doesn't allow fainer grained page border control if there are no smaller cells 
in print range (if there would be unmerged cells in print range it would be 
possible to drag these borders even if they cross the merged cell).

actually, there seems to be two problems :

1. unability to resize print range if there is only merged cell included 
(clicking anywhere to the right of first vertical border selects that border, it 
is impossible to select lower border);

2. in the light of this i also thought about cases when there would be single 
big cell. in this case oo.org insists that it all should be on one page (which 
is technically impossible). i didn't try to print it, though :)

so probably it would be good if it was possible to change print borders between 
cells (maybe some checkbox that would switch between "snap to cells" and 
freemode ?).

so it could be possible to handle issue 2. here and that would also fix issue 1. 
if issue 2. is found invalid, it's dropped. if it is found to be too big 
undertaking for now, i could file it as a separate rfe.