For the achievement "Custom-Made: Played through a Custom Playlist at least 15 minutes in length" note that you have to play the playlist in order. Do NOT shuffle it.
It didn't work the first two times when I shuffled. Got frustrated the third time and just played it straight through and cheevo popped.
Also, the Facebook and photo one had been glitchy for me. It finally worked, but after playing for weeks (see my post above, dated Dec 21st! wtf - that's how long it took).