[CentOS] xscreensaver lock problem resolved!

Hello to all:

I'd like to thank everyone who offered insight to why xscreensaver lock 
wasn't working.

Just this morning I performed a last-minute search, based on some leads, 
of possible pam configuration issues.  One URL that popped up via google 
was http://www.kernel.org/pub/linux/libs//pam/FAQ

Q9 contained a lead to make `which xlock` setuid root (chmod +s).  I did 
this for `which screensaver`, rebooted, and authentication worked!

So that was an unexpected change, but documented from a reliable source.

I hope this maybe helps someone else who may hit some of the same 
obstacles as I.

A good weekend to all, and stay tuned for more questions... :-)

Scott