Thread:Project:Support desk/unable to edit pages anymore

very strange: all of a sudden, sysadmins who always had rights to edit pages suddenly cannot. not all users but some. some can't even log in anymore. i don't understand why. when some of these users try to edit pages (and they definitely click save) the message pops up which says "Remember that this is only a preview. Your changes have not yet been saved!". I've double checked the permissions in LocalSettings.php and they seem all like they should be. I googled this issue and there seems to be some hits saying something about php saved sessions. If someone can enlighten me that would be sweet.

php version 5.3.3 mysql version 5.1.52 mediawiki version 1.17.0