I've been searching madly in vain, I can't find anything about this problem.
It's tough to debug, because when it occurs, of course the fucking Alt key is stuck on at a system global level, so I can't run apps and try to get information (you can't do an Alt-R to run something, and even clicking icons on the desktop can't run things because alt-click is something else).
If I knew where in the stack the Alt key was getting injected I could detect it and fire an Alt-down alt-Up which I think would clear it. But I assume the alt is down at a very low level and I'm not sure how to inject keys there. ( GetAsyncKeyState says alt is down ).
The easy solution is just to leave a keyboard plugged in to the mother fucker, which I might just do because I'm sick of dealing with this bitch.
In other random news : Chrome (the browser) is okay, but (A) fuck you for using a name that's generic and already been used by other software products, and (B) until they have a decent plugin architectures it's not usable IMO. I need Adblock and Flashblock and DownloadThemAll and PDFDownload, etc. and (C) I hate your custom bubbly buttons and menus; just use standard UI widgets you goofballs.
In other browser complainer news : I wish Firefox downloader replacements could actually *replace* the default downloader, rather than being a separate button. There are lots of websites that auto-start downloads or having weird buttons that fire the download rather than letting you just right click the file, adn those still go to the standard garbage downloader.