OK this is not one of your serious life-threatening issues, but it has
been bugging me.

Installed a new shower hardware set a couple months ago -- valve, tub
spout, shower head. It is a mid-range set from Price-Pfister. It's
very nice except: at first the shower diverter dingus on the tub spout
would drop down by itself after you turned the water off (ending your
shower), draining the water in the line leading to the shower head.
But now it doesn't; if you forget to push it down manually, it just
drips for hours but never drops back down. The old hardware did that
too -- it was an el cheapo, but I thought that problem would go away
when I put this nice, kind of heavy-duty new hardware in. Fondly do I
recall my halcyon youth, when these things just worked. So, why don't
they anymore? -- H