This is a problem I've been living with since I began using Word 2010 years ago. I assume, but do not know, that Word 2007 and Word 2013 behave the same way.

Microsoft Windows' standard behavior is to treat the Alt key as "sticky." That is, pressing Alt and then key X has the same effect as pressing the combination Alt+X.

In Word 2010 this doesn't work -- sometimes. After years of use, I still haven't figured out when it won't. It seems to fail most often with "Alt, I" and "Alt, A" combinations, but it doesn't always fail then, and it sometimes fails with other letter keys too.

The bug typically plays out like this: I'm touch typing, and I enter a key command like Alt, A, I, T (Insert Table). In my peripheral vision I notice that the display is grossly different than it would be if the command had been recognized. I stop what I'm doing, examine the screen, and see the text "ait" before the insert point. I backspace over the erroneous characters, press Alt, A, I, T again, and the command is recognized.

If I take eyes off copy to watch the screen as I press the Alt key, I can see the failure happening. Word should display shortcut letters over the ribbon names above the ribbon, and does not do so. When I press Alt a second time it behaves properly.

I'm astonished that even with the latest system patches, Word still exhibits this behavior after at least four years (possibly seven years). Is there any way to make it stop?

A word of context, before someone tells me to simply get in the habit of pressing Alt+X simultaneously. This is not a matter of changing a habit; it's a health issue. I have carpal tunnel syndrome in my left hand. I got it by stretching to press Ctrl+X key combinations in the days before Windows. With Windows I don't need the Ctrl key enough for it to be a problem, but I use the Alt key constantly. When I force myself to press Alt+X simultaneously, my CTS quickly gets worse. Fortunately pressing Alt, X in sequence lets me avoid this... except when I'm using applications that don't handle Alt properly, like Word.