Version:           0.7.3 (using KDE 4.1.3)
OS:                Linux
Installed from:    SuSE RPMs

I opened a two-page PDF, and both pages appeared (facing pages view mode) with 'fit width' zoom level.  The pane where the pages were displayed was of such a size that okular:
* would try to display the two pages at one zoom level, only to discover that it needed to insert scrollbars, 
* which would cause the client area for the pages to shrink, 
* which would cause the zoom to be recalculated to a lower number, which would happen to fit within the client area,
* which would mean that okular would decide that it didn't need the scroll bars any more,
* which would enlarge the client area again,
* which would change the zoom level,
* which would lead us back to the first step

The result was that the page view would toggle between scrollbars present / smaller zoom and scrollbars absent / larger zoom, a couple of times a second.

I could make it stop by moving the separator between the thumbnails view and page view.  It seems that it's fairly sensitive to the actual fit of the page view client area to the pages, both horizontally and vertically, so it may be necessary to fiddle a bit with view size.  It looks like getting the page view client area to almost exactly fit the two pages in 'fit width' mode is necessary.