Previously installed plugins not displayed in panel after update

Hey, I upgraded to WordPress 2.7.1 today (from 2.7), and while the plugins themselves are still working, they are no longer displayed under the Plugins panel, i.e. I can’t activate/disable them. The only way I can disable them is to delete the actual folders from my /wp plugin directory.

I took a screencap of the page so people can see what I’m talking about:

http://i32.photobucket.com/albums/d9/themovieaddict/FireShotcapture12-AddictiveThoughts.jpg

Any suggestions on how to resolve this?