I have one of the strangest issues I have come across. After upgrading to 8.1 my power button doesn't always work when trying to enter sleep mode. It's how I send my computer to sleep and wake it up. If the computer is off or asleep and I press the button it works every time, but if it is on and I press it to send it to sleep mode it works probably 25% of the time.

Not sure what specs will be useful so here are the main things: custom built computer inside a "Cooler Master Storm Enforcer" case with an ASRock Z77 Extreme6 motherboard, Intel i7 3770k, and Windows 8.1 Pro w/ media center.

Also as a side issue (that has been going on since before Windows 8.1) when I right click a word in Chrome to auto correct it that only works once per text entry. If I click the new word on the context menu nothing happens.