After upgrading to WP3.6 I'm getting the error
Strict standards: Declaration of PageNavi_Options_Page::validate() should be compatible with scbAdminPage::validate($new_data, $old_data) in /path/to/wp-content/plugins/wp-pagenavi/admin.php on line 156
I would suggest renaming the validate method to scbValidate? Your method definition is different to that of the parent class. Needs to be the same.