Version:           0.12.5 (using KDE 4.6.5) 
OS:                Linux

Similar to bug #186464, I have problems with screen updates in presentation mode.  However, in contrast to that old report, it does not give me a gray screen, but when flipping through pages only parts of the screen will be updated.  (Also, sometimes there seems to be a lag of one page, which is hard to say definitely if there's only a small rectangular "window" in which there is an update at all.)  Furthermore, I am using a stock (Ubuntu) KDE setup with kwin.

This is with an Ubuntu 11.04 (Natty, with KUbuntu's KDE PPA) system with the latest (280.13-0ubuntu1~natty~xup1) NVIDIA binary drivers (which I suspect to play a role here), installed via the "x-updates" PPA, see below.

Reproducible: Didn't try

Steps to Reproduce:
Happens everytime I open a PDF, press Ctrl-Shift-P to enter presentation mode, and try to navigate through the pages (normal & full-screen modes work fine).

In case anyone with a natty system (and maybe an NVIDIA) card wants to reproduce this, I have the following PPAs enabled:

deb http://ppa.launchpad.net/kubuntu-ppa/ppa/ubuntu natty main
deb http://ppa.launchpad.net/ubuntu-x-swat/x-updates/ubuntu/ natty main

Actual Results:  
After pressing Ctrl-Shift-P, the current / title page is displayed in the size of the original window in the upper left corner of the screen, the rest of the screen contains large black or gray patches / rectangles.

When using PgUp/PgDown, parts of the screen (i.e. a vertical rectangle, roughly but not exactly centered, overlapping with the above-mentioned small title page) are updated, sometimes additional small patches are updated after a while (without user interaction).

Switching desktops (Ctrl-F2, Ctrl-F1) lead to a proper screen refresh.

Expected Results:  
Correctly repaint the whole screen after entering presentation mode and when switching between pages.