I'm not sure whether this is related, but if your home page uses the Flash player to play audio or video, there is a bug where focus will shift away from the window. If you change your home page to the built-in home page or to a blank page (you can use about:blank as the URL), does that make any difference?

More info on the Flash and window focus problem: Opening New Windows and Shockwave Flash.

Incidentally, I have this keyboard and have never used any quick launch keys. When I get a chance to close Firefox, I'll test my Web/Home key and see whether it has the same issue.

Thank you for your suggestion.

I have always had my home page in Firefox set to blank, so that can't be it.

The same thing is happening in Thunderbird, which also doesn't get mail when it opens via the keyboard launch key, but does when opened otherwise. It seems to have something to do with this keyboard. Any other ideas?

I just optimized my registry, and that changed things a bit.

Now the 3 programmed quick-launch keys do open their programs on the screen, not just in the taskbar. But Firefox and Thunderbird still come up out of focus, and so Thunderbird doesn't check for mail.

Again, this doesn't happen when they are opened from the start menu, for example. It also doesn't happen to another program that is programmed to one of these quick-launch keys (Windows Explorer on the Search key).

None of this problem happens on my system when I boot my old O/S, Windows XP Pro.

So this appears to be some conflict between Mozilla's programs (Firefox & Thunderbird) and the newer 64-bit Windows 7 software for this Microsoft Ergonomic Natural Keyboard 4000.

Does any of that narrowing help?

Many thanks for any suggestions

When you launch Firefox using the Web/Home button, what window is focused instead of Firefox? You might be able to determine this by pressing Alt+Spacebar and watching for the window control menu of the active window.

The window that is focused is whatever the previous one opened was. If Firefox or Thunderbird are launched with no other windows open, nothing is focused.

After working with Microsoft's tech support on this problem over the phone, and replacing the keyboard driver & software with the one called Microsoft Mouse & Keyboard (both this and the one I had used are shown as the current drivers on Microsoft's 4000 Keyboard download page), nothing changed. Then I worked on the computer for a while, and the problem suddenly went away.

The only remaining problem is that Thunderbird doesn't search for mail right away when I open it. This is true regardless of how I open it (from the keyboard quick launch key, from the start menu, from a shortcut, etc.). Perhaps this is a totally different problem.

Thanks for your help.

There are some Thunderbird users here, but you probably could get better support for it on the dedicated support site here: https://support.mozillamessaging.com/