I have a leaking shower head, too.
I am having a similar problem with my shower head. I took apart the entire handle, replaced the seats and springs in the two holes at the back, replaced cartridge, bonnet assembly, and handle, but the shower head still leaked. When I removed the shower head, a lot of water sprayed out, then turned into a drip. I decided to see how much it would drip, or if it had ben fixed, so I left a bucket under it. In the morning, I checked it and the bucket was full. I am trying to figure out what is going on with it. If you figured out anything, let me know. I'll do my best to figure it out...if I do, I'll let you know. Thanks, Miranda