1) I think I've traced this to the workaround for the Chrome 'sticky keys' bug. The workaround prevents iframes from getting focus which means they never get keyboard input. So I've disabled the workaround when in an iframe, which unfortunately means iframed games will still get the sticky keys bug in Chrome... but I think they've finally fixed it in the next release (Chrome 18) anyway.
2) Gah, the new version of Closure Compiler I put in is buggy. I thought Google wouldn't release buggy versions of it. Reverted to the old one and it seems to work again...
3) Another case of the same bug, should be fixed too.
r79.3 on its way...