WP can't find pictures and behaves strangely

Hi,

My site just stopped working on its own some time ago (didn’t update or do anything). Now it can’t find pictures even though the paths are right and the pics are definitely on the server. Also everything is really sluggish and the control panel is displaying rather strangely as it is missing some colours.

I tried auto installing WordPress and repairing the databases in myPhpAdmin but the problem persists.

Link to a page on the site which displays the problem well: http://www.avantohelsinki.fi/avantolaiset/

Try clicking a picture, then even the header is lost. I’m baffled.