Alt+tab video bug; Sound bug
Two bugs I've found:
1) After ALT-tabbing out and returning to an on-going game, everything becomes darkened. It's as if something cast a shadow on all the buildings and units in the game. Resetting the video settings doesn't fix the issue. I'm playing on medium fidelity preset (although it happened in high fidelity preset as well).
2) I am playing a LAN game and I quit in the middle of it (to recreate the game). In the new, recreated game, my sound gets messed up. The music, voiceovers, and some random ambient sounds play, but attack and spell sounds do not. Adjusting the sound settings does not fix the issue. It doesn't seem like this happens in Internet games, although I've only left one of them in the middle of the game so I can't be sure. If I exit and restart the game, then there is no problem.