The smb.conf man page does not build properly from a 3.0 GIT snapshot from 26 April 2008.
The following two lines appear in the "middle" of the doc
EXPLANATION OF EACH PARAMETER
This error results in the "EXPLANATION OF EACH PARAMETER" section being pretty much empty.
*** Bug 5445 has been marked as a duplicate of this bug. ***
Seems to be fixed meanwhile.
Please re-open if it is still an issue for you.
Thanks for reporting!