Problems after theme change

WordPress version: 2.2.1
Theme now istalled: Web2Blog-inBlue 1.2

If i go in the menu for changing my theme i’m not able to see the preview of some themes, and if i try to install these the result will be a white page with all the elements messed up….
someone know what the problem can be?

there are also a few themes wich’s preview is available and they works fine.

i even tried to disable the plugins and changing the theme but i always obtain the same result

please help!