I installed the latest version (3.0) tonight and am still experiencing the same issue with inconsistent number of items per page. I have sent you a PM with the login and ftp info.
I haven't had a chance to try the revision to the query you PMed me yet, but I was wondering why the "PER PAGE" dropdown is defaulting to 0 on the pages? 0 should not even be a valid choice. With it set to 0, no categories or ads are displayed to the first time user.
Any idea how I remove the 0 option from the dropdown and default it to a different number?