Ok, so you did not follow the Ubuntu installation instructions like you claimed above....
I was kind of forced to vary as the night I was attempting to download 5.3.18 as defined in the Tutorial the system indicated that the file could not be found.
That was when I varied from the Tutorial and went to http://www.php.net/downloads.php
and found version 5.4.11, I simply didn't figure that the version change would cause issue...
Other than difference in version of php I did adhere however.