Can't upload background image

Hi, I’ve bought a premium theme (Crisp) and I’m having technical problems when attempting to make changes in my Theme Options.

Upload for custom logo and for background body image results in “page error” and I couldn’t even choose an alternative colour scheme (Theme Stylesheet) or link colour, whereas in my Playground Demo (http://test.woothemes.com/jequitiba/) everything worked well.

When I click the “Save all changes” button at Theme Options it takes me to a all-gray (if using Firefox) or white page (IE).

What is the likely reason? Uploads tool in the Media Library is running without any problem.

There’s another issue: some areas of my dashboard – QuickPress, WordPress Blog, Plugins etc. – appear permanently as “loading”.

Thanks
Pedro Biondi