Cannot get extensions to load

Hi all,

New problem I've not seen before... I'm working with the POWA query
monitoring package and have that working on my sandbox server. I want to
use this on several development systems here, but I cannot do a normal
install of the extensions needed as loading the postgresql94-devel rpm
wants to upgrade our current 9.4 installations to a newer version. So, I've
copied the extensions over to another system and have tried to do "create
extension <xxxx>;" on that system, but only the powa extension is loading.
Neither the pg_qualstats nor the pg_stats_kcache will create. What I find a
little weird is that psql keeps saying that it can't find
"$libdir/pg_xxxxxx" yet I see the .sql files and the control file in the
/usr/pgsql-9.4/share/extension directory. BTW, these are all CentO/S
servers, and the Db is 9.4.2. Could it be that since these were created on
my sandbox which is running 9.4.4 that the extensions just can't load or is
something else I don't see going on?
--
Jay