No sound in Mail, can't figure it out

I'm running 10.8.2 on a 2011 MBP17. I'm not sure when this started, but Mail gives me NO sound. Not the New Mail sound, not the ding when I check mail, the Sent Mail swoosh...all gone. Nothing.

I read about it happening for people where the sounds work fine, but after the computer wakes up from sleep, their gone. Not the case here. Even after a restart, still nothing.

Here's what I've checked:

- Mail settings - New Messages Sound is selected. Even tried other sounds.
- Use IDLE command is checked. I read that this was a problem for some, but not an issue.
- Repaired Disk Permissions.
- Notifications Center has the proper settings for the sound alert
- Audio Midi Setup. Read a fix about opening that app, changing the format and back again, which should cause all backed-up sounds to play. Didn't work for me.
- Did a force quit on coreaudiod in Activity Monitor, which I heard can work. Didn't.
- I don't have Power Nap on this machine, so that's not the issue (was for some)

I do get audio from audio attachments, for what that's worth. But I've tried everything I could find on the issue.

Anyone have a similar problem and come up with a solution?