Environment: Ubuntu 8.10
When enabling PHP extensions in the GUI, status changes to ERR, and this message is displayed in the extension's message column: The system could not load this extension. The regular yellow notice box at the top of the page still says "The extension 'calendar' will be turned on after the PHP is restarted", and it works when I restart the server (i.e. the calendar extension is enabled). There are also other oddities. see the attachment.
It seems to be a GUI problem that only occurs when an extension's on/off status is changed without restarting PHP.
(I'd show this in 7 attachments with text comments if possible, but the forum only allows 3 attachments per post)