Apple wireless keyboard only types caps

Found this on several other discussions but it was the first time it had happened to me.

Using an Apple wireless keyboard with a Mid 2012 MacBook Pro, 15", non-retina display. All had been fine but all of a sudden the wireless keyboard would only type caps. Hitting the cap lock button turned the light on and off but the keystrokes would produce nothing but caps. Additionally, clicking a link in web pages would only add the link to the reading list, instead of going to the link. Not sure if it is related or not but I suspect it is.

Tried several things found in other discussions - replacing batteries, restarting, repaired permissions and the like. Even trashed the cashes folder prior to a restart. This allowed the keyboard to respond correctly but only for a couple seconds, then it reverted to all caps again.

What fixed it for me (as you can see I am now typing in upper and lower case) was disconnecting the wireless keyboard via the Bluetooth menu in the menu bar, a suggestion I saw on another page. Don't delete it, just use the disconnect function, wait about 10 seconds then reconnect via the same menu.

So far so good, but I also just noticed that the shift key was stuck in the depressed position. Not sure how it got that way but I suppose that could have been part of the issue although I never saw anything like mentioned in other discussions.

Jeff