Interesting. Yes, you understood what I meant, it's strange that you can't reproduce it. Maybe it does depend on the windowmanager used. Either way, I haven't used it in a while now - I did use it when reading lots of PDF's while doing research for a paper. I vividly recall how I disliked Acrobat, as it was far less nice to use for reading. I actually went home behind my own computer screen to read, rather than doing it at work (where I only had windows available).
But I guess everyone's habits are different, as are preferences ;-)
I just wanted to illustrate a very small yet nice feature Okular has which makes it (to me) nicer than Acrobat. It has more of those, of course ;-)