Hi 
At a guess Scribus probably have their own forum/mailing-list and you
might get better answers from them.
Are you creating the document in Writer first and then opening it with
Scribus later on? Did the Scribus document start as a fresh document
within Scribus and using their native format or did it start out in
another program such as Word?
I found that of the few documents i have trouble with in Writer if i
start a fresh new document and then copy&paste in the old contents
using "Paste as unformatted text" then almost all troubles i've had
with the document vanish. A couple of times i've done that within
LibreOffice. Going from the 1st branch, 3.3.x, to 3.4.x or either of
those to a 4.x.x it seems to help to go through that process again.
The 3.3.x seemed very unripe, but all later ones have drastically
reduced the occasional need for that sort of faffing around.
So with a different program i would advise creating a fresh document
in that program and then try to bring in elements with as little
formatting as possible. Ideally go back to original images rather
than moving them from one document to the next.
That seems to raise the quality from 80-90% up to around 99% on those
rare documents that seem grumpy about weird things.
Regards from
Tom 