I didn't do any of the initial steps they recommend one does before doing the SMC reset.

I'll try that in the order they suggest.

Thanks!

First, don't shut it down with the button; shut it down with the menu. It's trying to cache, and shutting it down with the button just makes the problem worse. Shut it down with the menu and wait - with an older machine, it could take 10 minutes or so for it to finish caching.

If it takes longer than that, take it to an Apple Store.

Assuming it *is* a caching issue, will allowing it to go a long time and ultimately finish, will it cache much faster the next time?

Faster - not super fast - but faster ... and assuming that's the issue (not Mail running a zillion threads, hardware issues, etc).

Wait a few minutes, then reboot and immediately open Console (Applications -> Utilities -> Console)

In the sidebar, right at the too of the Files list, is a file called "system.log". Click on that and scroll back past the startup stuff to the shutdown messages (look at the timestamps, they'll abruptly change by a few minutes once you're beyond startup). That should give you an idea of what's hanging up and at least where to start searching for a fix. If it's incomprehensible gibberish to you, let me know and I'll tell you where to email a copy so I can look at it. The UNIX layers of OS X are incredibly handy if you know how to use them.

. . . . I got it to normally shut down a few times, but now it seems again to be hanging. My gut says it is related to either mail or, more likely Firefox.

I will take a look at the log file tomorrow. I may or may not know what I'm looking at. If I need an interpreter, I'll let you, for sure! Thanks for the offer!

If all your apps have quit cleanly before you shut down, it's probably something a little more devious...hopefully the log will make it clear though.

Let me know if you need anything!