I finally got my beloved KPDF working again on Ubuntu! Whoever jARLAXL is, I heart you.
What an exercise in frustration this was. Now, I have a lot of scanned documents which are quite large, so a fast PDF viewer is essential. At home I use an older version (say, N-2 or N-3 where N is the most recent release) of Adobe's reader, with all the stupid plugins disabled.
But on Linux? I won't even rail on KDE 4 in general, which was so bad it forced me to switch to GNOME. But for kpdf they took a program which was blindingly fast, did exactly what it needed to do and no more, and replaced it with a generic document viewer ("okular") which was neither. Who needs a "generic document viewer"? Answer: NOBODY. Windows tried this ages ago in Windows 95 and nobody uses it any more. File formats move so fast, that making a single program try to span them all is pointless and stupid for many reasons I could care to regale you with off the top of my head.
Other possible solutions?
1. Use "evince"? The horror. Can't do image filtering, so full-page views of scanned documents are illegible. Shows "Loading..." instead a low-resolution preview when loading images. Printing is unbearably slow and you can't tell when it's done spooling. I literally could not figure out how to print for a few days, because I would tell it to print a 100-page document, and it would start chugging away with no feedback that it was busy. I'd then quit, and it abandons the printing, again, with no feedback whatsoever. Can't search or copy text.
2. Use "acroread"? A pain to install, enable this repository, import this GPG key, blah blah blah. Not as fast as KPDF with a totally ridiculous user interface, filled with zillions of options and plugins I will never, ever use. I want it to: Display the document fast. 2: Print the document fast. 3: Extra features should never ever get in the way of #1 and #2.
3. Use "okular"? Ha ha ha! KDE 4? Ha ha ha! Are you kidding?