White screen of death only in wp-admin

I’m able to log into the website but the moment after login, I get a white screen in wp-admin. I can still access the website and it shows that I am logged in with the toolbar at the top of each page but whenever I venture off into wp-admin, I’m met with a white screen.

I’ve tried renaming the themes and plugins folder, even deleting both. I’m tried increasing the php memory limit to 128M but still no luck.

Any advice? If I do have to reinstall WordPress, how would I not lose everything that is already there?

EDIT: I’ve also turned on debug but still do not get any errors, warnings or notices.

As a rule of thumb, always remove the ending ?> of your .php files, especially if it’s a functions or config file that gets parsed before headers are sent to the page. If after that ?> you accidentally add a space, a tab character or a new line, there’s your invisible error.