I just upgraded http://kcadp.org to WordPress 3.0. The site looks fine to visitors and everything on the the backend appears normal--except I'm no longer able to add new posts. http://kcadp.org/wp-admin/post-new.php just leads to a blank page. (I am able to add pages.)
I had this problem in both Safari 5.0 and Firefox 3.6.5 on a Mac running OS 10.6.4. logged out of the site and back into it. That didn't fix the problem. Not sure if it matters, but the site is hosted with Earthlink.
Any suggestions how I can fix this problem and add new posts? Thanks!