I just replaced the tub shower diverter and the whole apparatus came off while showering. I redid the whole thing and tighted better, but now there is a leak. I read previous posts which instructed to sand the copper pipe and rethread plummer's tape, however when I went to do that, I noticed that the pipe coming out of the wall actually has a slow drip coming out intermittently. Is this normal?

Remove the spout. Check the O-ring. It clips very easily. If damaged, replace it with new one. Apply lubricant on O-ring before you slide spout over the pipe again. Tight with allen wrench well.

I noticed that the pipe coming out of the wall actually has a slow drip coming out intermittently. Is this normalUnless it's a steady drip I wouldn't worry. What it sounds like happens is that there was a burr on the end of the copper pipe that caught the "O" ring and rolled it out of position. Make sure the "O" ring is back in its slot and that there aren't any burrs and like Milo advised, "Apply lubricant on O-ring before you slide spout over the pipe again. Tight with allen wrench ."'Goo0d luck, Tom

When I pull up button to divert to shower only, water still comes from faucet, lessening pressure to shower head.