Make the check for both type of scrollBars run in "parallel", i mean, to check both of them and then exit if one of the scroollbars is not present.
Done Christoph, Thomas and Alex issues.
(The blank spaces are already removed)

A Question: Could this be done in the rowsInserted method?

Basically, what I do is:
If there are one or zero columns, hide the horizontalScrollBar until it is needed. (it has worked in the past, but in another file).
Apply the same strategy with files.

Additional stuff:
Moved the common calculus of itemSize outside of the if then else.

Krunner config does not loop (neither kgetnewstuff from kstars). I can not test with amarok (I've hit by an amarok start bug).
Please, test with other programs.