I'am not sure what the problem on your system is at is really uncommon and I can not tell you more without checking the server setup. There are about 20 thousand new ispconfig 3 installs per month and as you see, there is nothing on this topic in the forum.
There must be a problem with the initial server install on your system. Most likely your system admin did not follow the installtion instructions from the perfect server tutorial closely when he installed ispconfig on your server. The tutorial that you used in post #8 is not for ISPConfig, so your system might not work if you use that.
The Tutorials that should be used to prepare your server for the ispconfig install are listed here: