So when you creating plugin and there is admin page for your plugin you can get error You do not have sufficient permissions to access this page . This is easy to fix: in your plugin file  you have such code:

add_action('admin_menu', 'rotator_bar_admin_actions');
 function rotator_bar_admin_actions() {
 add_options_page("WP Rotator Bar", "WP Rotator Bar", 'read', "rotator-bar", "rotator_bar_admin");
}

so 4th option for function add_options_page should be the same name as your main plugin file for example my one is rotator-bar.php, if you have different name there you will get error above

There is situation: you install new wordpress blog, insert config data but when it goes to the http://[yourdomain]/wp-admin/install.php you get just blank screen. There can be few reasons, but when it’s your first installation probably you have memory limit issue on you server. You can fix this by adding line below in your .htaccess file:

# increase memory up to 32 mb, if you need you can make this amount bigger

php_value memory_limit 32M

If this does not helps, then you should add this line to your .htaccess file:

php_value display_errors  ”1″

This will force PHP to show what error cause blank screen, and when you know problem it’s easy to find solution

While in admin panel of wordpress you are trying to updatd some plugin through auto-update feature does it fails ? You getting something like this: Can not connect ftp …:21 ? You insert all valid data: FTP domain, ftp user, password, choose option through FTP or Secured-FTP and it’s breaks again? Then you should to try enter localhost instead of your actuall ftp domain, it should fix problem.