ZBrushCentral

couple of problems

I have a couple of problems in zbrush

the first one is that when i open the software all the demo models are gone.

and the second one is the f key. when i press the F key my zsphere is resized to a very large sphere and its not shown only inside the work space(its covering the whole space but it should fit).
i tried it on a 350X350 document size

thank you in advance

Ben