One thing to watch out for here, which can cause confusion when
reading man pages.
I did an update install of Leopard over Tiger on my MacBook. It was
only later (while working over the phone with the boss and finding
different options listed for a command on the man pages on his Leopard
machine and on mine) that I found that the man pages on the MacBook
were those from Tiger. (The programs themselves were those from
Leopard.)
All was well on my other machine, where I did a clean install and then
used Migration Assistant to bring stuff over from a SuperDuper clone.
(I cleaned up the MacBook by doing a clean install and using Migration
Assistant to copy from the TimeMachine backup [I had two bootable
clones in reserve].)
--John