problem is solved - it seems every one of you had some rights as the problem was lying in the profile - but Silas Awaketh was indeed right. I found it the hard way unfortunately, the urlfilter.ini file in profile directory contained '*' entry in [Exclude] section -> basically that could be seen in Tools - Advanced - Blocked Content and deleted from there as well.

Comment avoir son navigateur à genoux sans avoir aucune idée de ce qui se passe.