Unable to save user information
 

Please help!
During the installation of phpwebsite 1.6.2. I encounter a following problem on "Installing - users" page. Whatever information I enter (username, password, email) - I get the same page, saying "There was a problem in the installation file: Unable to save user information."
What may be the reason for that and how may I solve this problem?:( Please help, cause I have no clue...