Sounds like a Clue mystery to me: It was the nefarious Mr. Green with the lead pipe in the Library! …only a certain Lion is responsible for this one.
Have you noticed that your User Library is no longer accessible in Lion? Well I did, and I wondered immediately how I could get it back. I mean, I’m partial to my Application Support, Mail Downloads and Preferences folders, to name a few, and thoroughly enjoy being able to muck up access that data. There has to be a way, I thought—and there is.
I understand why Apple moved away from providing accessibility to the User Library (most people arguably wouldn’t use it enough to warrant it), but if you’re pining for it, run this quick fix in Terminal:
chflags nohidden ~/Library/
Case closed!