I'm running a fresh install of Mint 16 on an essentially-brand-new Dell Inspiron N4110. I booted to Kali Linux initially, and noticed AltTab, AltF4, and AltD (address bar focus) weren't working in Iceweasel, which I dismissed as a minor glitch or a missing driver or something. After downloading & installing Mint, the Alt key still does not work.
xev shows absolutely nothing during an Alt keypress (LAlt or RAlt).
I've never had this problem before, and Google isn't turning up much. Has anyone else seen this, or have an idea of where to look? As far as I can tell, the rest of the keys are working fine, and the Fn key is in "normal" mode (F12 = F12, as opposed to F12 = Mute).