Hm, i am nearly sure, there was a former plugin (maybe an other one) that managed to get the text away in order to use the space for reading. But maybe I'm wrong.
I tought, that somebody has got an idea how to solve this issue. As I'm messing around with this problem since the first day I wanted to read a PDF file, a solution would be really appreciated.
Well, if it is not possible i will have to deal with it.
The text itself wouldn't be a problem for me, if the rest of the page would "rescale" so that no content disappears behind the page number. Moreover I noticed the used space for this text doubles(=about 2.1cm) when you flip the page, but this is a phenomenon that is only related to one special PDF (which was actually a power point presentation)
However, thank you for dealing with my problem!