Well I think I resolved this, but I think it's a but that either needs to be fixed with ispconfig or an addition to the perfect install howto for Cento 5.x
By default the "requiretty" option should be OFF, but in a Centos 5 install, it is set to ON, so I had to comment out the line to change back to it's default of OFF.
Now my stats are working fine, however I still get lines like below each time someone checks stats on ispconfig. Is there anyway to set the TTY, so we don't get these errors?
Aug 3 05:38:20 server1 sudo: admispconfig : TTY=unknown ; PWD=/home/admispconfig/ispconfig/web/multidoc/edit ; USER=root ; COMMAND=/usr/bin/du -h --max-depth=1 /var/www/web9