by Ken Task.
Didn't mention OS but assuming (by the word 'root') that it's linux, soooo:
What do you get when issuing 'whereis php' and then 'which php'.
It is possible to run two versions.
The 'other servers' are running what version of Moodle?
fgrep '$release' /path/to/moodle/version.php
'spirit of sharing', Ken