All links broken

I´ve got big problems with both my websites (using the Karolina theme). All of a sudden most of my internal links are broken! You just se the message "Error 404 | Nothing found!" I have hundreds of internal links on my websites, which are about two singers; links to concert reports, newspaper articles, videos etc. It would take days to make them all over again. What can possibly be wrong??

Also the front page looks strange in IE and in Firefox. The font is suddenly different, and the letters much bigger. The menu was before in one single line, now suddenly there are two lines with links in the menu. Help!!

http://www.andersekborg.nu/

http://www.helensjoholm.nu/

I´m so sorry I bothered you with this topic, I found the reason to all my problems now: The widget "NextGEN Gallery by Photocrati", which was updated a few days ago. When I deactivated it both my websites looked perfectly normal again, and my internal links works fine, puh!