This post is just a quick heads up for those of you that have WordPress blogs and are planning to upgrade to WordPress 2.8 (the latest subversion which is 2.8.1 2 has come out recently). You might encounter a problem which I just did when I upgraded using the Automatic Upgrade option (which IMHO is the best feature of WordPress since version 2.7). After you upgrade, when you try to log into your Admin, you might get an error message which goes something like this (depending on your plugin and domain name):
Fatal error: Call to undefined function is_site_admin() in /home/user/public_html/domain/wp-content/plugins/sem-google-analytics/sem-google-analytics-admin.php on line 20
The problem is caused by the now obsolete function of certain plugins (like Semiologic Google Analytics – A great plugin by the way) which utilize the is_site_admin() function. The WordPress 2.8 admin only uses the is_admin() function.
I have to give props to a blogger (Ixibo) for mentioning this, and sparing me having to delete/rename the plugin that was causing the problem. Yes, a common solution for wayward plugins is to delete or rename the plugin folder. You don’t need to do that in this case or deactivate anything.
Simply find the copy of the plugin on your local computer, and open up the plugin files with Notepad and do a Search and Replace operation. Just search for all instances of is_site_admin() and replace them with is_admin() and then save the new files somewhere and FTP those files back into your hosting.
Voila. Your WordPress Admin should now work again.