Ok, we're repeatable:
It's starting to look some some sort of hardware quirk with this Compaq Presario CQ60z
It happens with 32 bit TC 10.1 (not tested on older releases)
It happens with 64 bit TinyCorePure64 10.1
Bare naked ISO's burned to different sticks with no additional extensions.
And, when booted to the command prompt only, it happens there too after about 20 seconds.
Fascinating, Jim.
Something in the Compaq is tickling the kernel late. No amount of waitusb=xx fixes it either.
The solution for now seems to be just wait 30 seconds for the poltegeist-keystroke to appear and then move on.
I can't avoid it when booting to the command-prompt only, but in the gui environment, if I wait 30 seconds and fire up aterm, I never see it as the trigger for it has already passed.