It´s kind of difficult to work with Pf 6.4.0, because I can´t see the full selected area while marking it for crop or other funktions. I´ve uploaded a screenshot in order to show, what I´m meaning.

I didn´t have the problem with older versions, but they were crashing quite a lot with error messages, so I downloaded this version. Is there a way to fix the problem? I´d like to keep working with pf, if possible.
I´m using Windows Vista Home Premium 32bit and an ATI 4850 graphic card with 512 MB, in case it matters.
Thanks,
Shinryu