Unable to upgrade to 3.0.1

I’m using 3.0 and after that upgrade am no longer able to add new posts. (http://kcadp.org/wp-admin/post-new.php just leads to a blank page). I was hoping that 3.0.1 would allow fix that problem. Unfortunately when I try to update my WordPress install, I get this error message

Downloading update from http://wordpress.org/wordpress-3.0.1.zip…

Unpacking the update…

Could not create directory.: /netapp/whnas-silo1-node1/s8/s8/01264/www.kcadp.org/webdocs/wp-content/upgrade/wordpress-3.tmp/wordpress

Installation Failed

Any suggestions? Thanks!