my Blog doesnt show up, posts do !

Hey all

I installed wordpress and it is running perfectly, suddenly the official address of the bloe stopped working, it loads but a white page (no error messages like 404):
http://www.al-rasid.com/blog/

However, if I visit an internal link like that of a blog entry, it loads:
http://www.al-rasid.com/blog/index.php/2007/04/30/the-mark-of-cain/

From within that entry that loads succesfully, If I click on any of the categories, or archive links, I get the same white page, only Pages load without problems.

So where is the problem ??

Thanx