NinjaBoard Fatal error

hi, I just installed ninjaboard but when I try to add a post or to reply to a post this error appears:

Fatal error: Call to a member function update() on a non-object in /home/xxxxx/public_html/components/com_ninjaboard/system/ninjaboard.editor.php on line 160

Also if you choose Ninjaboard - Style Black, no css styling is applied to the board