Problems with caps lock

Following the latest software update for my MBP,my caps lock key has stopped working! Don't know if the two events are connected via a glitch in the software that has disabled the key, or if it is a coincidence (but I had no problems with the key previously). Has anyone else had a similar problem?
Any suggestions for things to try?

Have you tried rebooting the laptop?

Sure have tried rebooting - at least, I've tried "restart" a couple of times. Or did you have something more drastic in mind?

Try this: System Preferences > Keyboard > Keyboard. There should be a button in the bottom right corner that says "modifier keys". Check to make sure that the "Caps Lock" key is set to perform the action of a "Caps Lock" key. If it is not, then that is your problem.

Thanks for the suggestion. Regrettably, it's one I already checked, and it was set correctly. My developing guess is that it's hardware.

Pop that key off and see if there is something under it preventing it from working. A sesame seed for example could be the culprit. The keys come off easily. I've used a paper clip successfully in the past. And you just click them back into place with a little down pressure.

Genius! Thanks - it worked.

Mind letting us know what was small enough to fit under there? Or what you found once you popped it off?