MS Office keyboard: Special Office keys stop functioning?

Suddenly the keys for Word, Excel, Cut, Copy, and Paste on my MS Office keyboard, no longer function. If I click on the icon for the keyboard and then click on each of these keys, and Edit, they will work, but only for a time.

Two questions: The first is can this be corrected? The second is could my keyboard simply have worn out, or at least could those keys have worn out? I use them a lot, expecially if I'm online.

Thanks for any help anyone can provide.

 

Office keyboard

Further info: I uninstalled and reinstalled the keyboard and it worked fine - for a week or two.