This is a known problems (just google the subject line)
There few problems/bugs in this program:
* No way to disable transitions from the UI
* Each transition consist of many small steps of fixed number of pixels, so the number of steps grows with screen size.
* The calculation for how long to wait between transition steps does not scale well (or at all) with screen size.
* The total transition time may be longer than the slide display time.
* There's a config file setting to disable transitions, but not in our version. (I think it was added to 4.7.)
The above problems render the screensaver slideshow unusable.
After reviewing the source code on kde.org, fixing the above seems trivial. The revision log shows no one is interested though.
http://websvn.kde.org/trunk/KDE/kdeartwork/kscreensaver/kdesavers/slideshow.cpp?view=markuphttp://websvn.kde.org/trunk/KDE/kdeartwork/kscreensaver/kdesavers/slideshow.cpp?view=log (Revisions 1235612/3)
I'd like to fix that however I need a source copy of kdeartwork4-kscreensaver-4.6.5-1pclos2011