I investigated further and found that the problem is not in Office 2010; it's in Windows 7. I was not able to duplicate it in XP (which I still use, but rarely) and I was able to duplicate it with other applications.

I've been under the misimpression that Office was the source of the problem for years. I'm rather embarrassed by that. As an excuse, I can only plead that based on my previous experience with Microsoft, I thought there was nothing to be done. Thus I never did the investigation that should have cleared up my initial false impression.

So this is the wrong forum for my question. Since I've raised it here, though, I'll pursue it and see where we can go with it before I try elsewhere.

When you said "The behavior you describe is not standard..." I'm not sure whether you meant the fact that "Alt, X" is equivalent to "Alt+X," or the fact that in Windows 7 it sometimes doesn't work. I've never seen a direct statement that using "Alt, X" is supported behavior -- why would I look for one? -- but over the years I've used it on my current home computer, first with XP and now with Win7; on my old laptop and my current laptop with XP; and on more work computers than I can count.

Have you tried it? Perhaps you think it's not standard behavior because you simply weren't aware of it.

You asked if I've got the adaptive sticky key feature turned on. I do not. I know it's there, but I've never messed with it. Just for good measure I checked the settings on my current work machine, and none of the adaptive features are on.

You suggested that it might be "the sensitivity of [my] Alt key." My comment about the number of computers I've used applies here too; only the Win7 computers are relevant, but there still have been more of them than I can count, and each has or had at least one keyboard. (I use/used each laptop with at least two keyboards, of course). I don't think this is something I need bother testing out.

I've been aware of the Dvorak keyboard for a long time, and tried one once. I concluded that it was interesting but not practical for me. Apart from the obstacle of learning a new keyboard after 50 years of QWERTY, I'd face the problem of switching back whenever I have to use an unplugged laptop, or have to work on a machine other than my own. In any case, the Dvorak keyboards I looked at just now (at least, the ones with photographs detailed enough to show) have ShiftLock/Ctrl/Alt keys in exactly the same places as any other PC keyboard. I don't see the payback in learning to use a different keyboard layout, and putting up with the resulting complications, if it doesn't solve my original problem.

(And another potential problem just occurred to me: the Dvorak layout puts more of the most often used keys under my left hand, which is my CTS hand. Consquently it may well be worse for me than the standard layout.)