Windows 7 - wake up PC by pressing spacebar

This has worked on my pc's  for years, until ....
I have a few systems and an A-B-C-D switch for monitor/keyboard. Normally
I am on B for my XP clone. A few weeks ago I used the Lenovo on A.
I have noticed since I am back on the XP box (on B) that pressing the spacebar
(or mouse) to wake up from either standby or Off only works about 20% of the
time: the other 80% I have to press the power button. I went into BIOS and
played with S1&S3 and mouse vs keyboard to see if any difference. None -
flaky no matter which setting/which device wakes it. Any ideas ?
XP SP3 , Asus A8N-e motherboard

What happens if you swap the wire sets, such that the port B computer
is now on port A (and the port A computer is now on port B) ?

Does it work any better ?

After doing that test, does it look like a KVM problem or a computer problem ?

If moving it helped, it is probably the KVM. Also, keep track of your
wire sets, in case a wire is flaky.

Paul

Update:

spacebar DOES work if pc is previously turned OFF.
But does not work in standby 90% of the time.
Thoughts on how BIOS "Power" 'should' be set.

If it works when the PC is off, I am not sure there is
any user control that will help it come out of standby.
That should also work.

it is up to the OS and BIOS together, to put the hardware
in a state where a keypress will wake it up. It could be
a BIOS bug or a chip design bug. (Just like my VIA system
does not do S3 suspend to RAM reliably.)

Paul

If you missed my first post ... It was fine for years on this PC. until a
few weeks ago I switched my KVM to another PC. Next time I used this one the
spacebar power up was flaky.

Would the KVM be "switched away" from that port ? Perhaps the
reason it does not work, is the KVM is pointed at another computer ?

I do not own a KVM, and know nothing of their quirks.

Paul

This box is not anything fancy - it had ABCD switch on front and 5
video/keyboard connectors : 1 each for A, B, C, D on back and a common one
of each go to my desktop monitor and keyboard.
I am using it now on B and both work. My suspicion is the pc BIOS, not the
box  but I cannot find a simple explanation of S1 & S3 power setting online
as far as the difference in waking it up.
Why one would work with spacebar and other not ?

The Device Manager has the setting. As far as I know, the OS passes this
info to the BIOS, during shutdown. And on my machine here, this even seems
to work, when the BIOS setting for the keyboard is disabled.

http://img209.imageshack.us/img209/8371/wakeup.gif

Paul

Paul,

Please ask some woman nearby to give you a big kiss.
My keyboard- power mgmt box was unchecked.
I do not know how or why it got UNchecked, but it now works.
Thank you.

YW,
Paul