"J. P. Gilliver (John)" wrote

| What happened with checking for faulty hooks? You
| ruled that out? If it really works as you say then it
| would seem that would have to be a Windows problem.
|
| I'm afraid I must admit I felt that was beyond me.

I was thinking the same as Java Jive. Try disabling any
keyboard funny business from boot and see what that
does.
To check for malware you could try the usual: AV,
rootkit hunters, etc. Then maybe look at process explorer
and inspect all runing services. You could have a malware
service, or you could have a legitimate service that's
faulty.

Example: Say you have a tool that italicizes parenthetical
text as you write. That program could be written to watch
for keycode 48 + shift and do it's thing at that point. If
the code was faulty it might have a bug that could do
something like stop letting the message through by
mistake after the first catch. That's an easy bug to produce.

If it happens in all software then that indicates it's
systemwide, again pointing to some kind of keyboard hook.
And since it starts unpredictably and clears at startup,
that's another clue indicating it might be some kind of
faulty code that screws things up once it runs. To use
the example above, your tool watches for 48 + Shift but
then the programmer forgot to pass the message along
once it's been dealt with in that tool. In other words, a
bug in a keyboard hook could "eat" keyboard messages
in an unpredictable manner. It could even return the ability.

When you talked about this last time I looked up hooks
but didn't find anything that seemed to be a way to
list active hooks. Windows apparently doesn't keep a
publicly accessible listing. So you just have to narrow it
down by looking at running processes that could be
hooking the keyboard.