For anyone having trouble installing the forum, just delete the phpBB2 folder and then reupload it with a blank config.php (chmod 666)
and go to
http://www.yoursite/phpBB2/install/install.php
I was getting different errors, but ounce i did that (the above) everything went smoothly.
Edit: I tried another install and got errors again when trying to install the forum, I checked the permissions on the phpBB2 folder and it was chmod 777, when i changed it to 555, the errors went away and it let me install it.
Doe's anyone know what the proper permissions on this folder should be ?