Al,
The loose stem(s) were on my outer drives. I had all new tires in January at a good shop. When I had to install different stems on the outers to work with the PP monitors, a local shop swapped the stems for me. I think that is where the failure-to-tighten occurred.

I really wanted to avoid extensions for the inners, and looked at the options. For me the ability to install/remove the PP monitors, manually check and adjust pressures lead me to use extensions only on the inner drives. I do use the rubber bushings in the outer wheel to somewhat stabilize this necessary evil.

Thanks for the input.