ghostscript for printing fine: gv+ghostscript dysfunctional

I have ghostscript under cups working fine, for printing. all my
gnomeish apps are happy. made in pkgsrc. no funny tunings.

But, gv calling gs/ghostscript (in some way) is deeply unhappy and well
over half of the PDF I look at are unviewable

	repaint incomplete (garbage from previous page left on screen)

	screen blanks immediately page view completed

	gs terminates view precipitately.

these seem to be things which wouldn't affect any physical print
device, they are all post-page-throw outcomes which really only cause
pain on a display.

acroread is ok, but I'd rather not have to dive into /emul land.

Anybody have a clue-by-four they can hit me with?

-G