The problem is half-way fixed. I did not find the class ".currentli_item" in style2.css, so I added it and then replaced it with ".current-menu-item" - then it worked.
Two problems still remain:
1) Before I tell you what the problem is, I think it will be fixed if you answer this for me. How can I create a "Home" menu, which would load the home page that shows all the posts? Right now I created a hyper link and this does not work with the menu link color problem we have.
2) Please look into providing a fix so that the active pages shows the active link color regardless of how it was reached.
You replied with: "I am not sure if the second problem can be fixed, since there seems to be no connection made by wordpress between those posts and the menu item... "
Thanks once again,