CentOS 5 Networking :: Pptp Vpn Not Working ?

I can't get the CentOS version of pptpd to work. I have a Debian 6 one with the exact same setup that does work. The required port is open according to various external port checking websites. It's giving me random errors when trying to connect, including 800, 809, 619. This is what I did so far;

Step 1. Installing pptpd the pptpd is the daemon that runs the pptp server.

To install this:

Step2. Next you will need to modify the pptpd.conf

Step 3. The vpn server is now configured and now you must setup authenticated users:

Step 4. When pptpd was installed it started automatically so we will need to restart it to apply the changes:

Now, if you would like to add internet access over this vpn, you can do this:

And find the line for ipv4 forwarding and make sure it = 1:

Then use iptables to get the net forwarded: