Help! I can't put music/video into my iPhone in iTunes 11!

So... I manually manage music and video in my iPhone. I've configured iTunes to show the sidebar and column browser. The iPhone shows up in the sidebar but I cannot drag and drop music into it as before. When I drag a song into it, the iPhone image highlights in the sidebar and the cursor turns into a green + sign just as if it's working correctly. But nothing happens. The song doesn't get transferred.

Also, I can't create an iPhone playlist. When I click on the iPhone to highlight it, the Plus icon at the bottom of the window is un-clickable. So far the only way I've found to add music to the iPhone is to create a new playlist in iTunes and then drag it to the iPhone.

I hate iTunes 11! There is so much that is broken or hidden that it's unusable. I cannot believe Apple released this, let alone praised it as a major upgrade.

I don't have time to troubleshoot this or call Apple Support. What on earth were they thinking - or smoking - in Cupertino when they redesigned this?