"J.Lef" writes:
As always, you guys are the best. You are right and the
fault is on our end.
For some reason, it seems that the 3 way bulbs got a bit loosened. They
were turning on and off, but not three way.

The construction of 3-way bulbs and sockets is that you *always* get
contact on one of the base contacts before the other. So you get
one-way operation first, then 3-way after you screw the bulb in far
enough to make the second connection. But with a bulb and socket that
are properly set up, it shouldn't take much rotation (or much force) to
go from 1-way to 3-way operation. So it's possible that one of the
contact fingers in your socket is too far from its normal height (e.g.
one may need bending up so it contacts earlier).

Dave