For some reason this morning when I go to login to /wp-admin/ on any sub-blog, the /wp-admin/ is blank, while it worked fine yesterday.
The blogs themselves work fine and the associated plugins work fine, I just cannot get in to the admin. I've tried two different computers on two different networks to rule out network proxy caches and browser issues.
I've tried removing all plugins from the MU and regular plugins directory, which didn't help.
PHP has not been upgraded since February, I've tried increasing and decreasing the memory limit in wp-settings and I've tried creating a php.ini and disabling Zend for my /blogs/ directory.
I know I could probably upgrade to 3.x, but I find upgrading things break since in my environment I __MUST__ have www. in front of URL's.