I have posted my problem to the "Installation" forum, however it was a mistake.
My WP doesn't work due to corrupted Firefox profile. You can see it in the following picture: http://www.ists.pwr.wroc.pl/~wthomas/wp.jpg . My WP works fine with IE, and with FF it doesn't display any posts - however number of posts to the left ("Uncategorized (1)") is displayed correctly. There are no sections Blogroll and Meta as well. I can't see any posts in Dashborard / Manage / Posts.
I am so confused. PHP is server side language, so it should not depend on corrputed profile of my browser. I understand that FF and IE render pages the different way. But "Not Found" posts?
I am using only FF in my day-to-day work, so for two days I have been trying to repair starting setup of WP.
Have you got any idea about reasons?