In edit mode I press and hold down K but nothing happens! Knife doesn't work

In edit mode I press and hold down K but nothing happens! Knife doesn’t work. Shift-K doesn’t work either. Checked keyboard shortcuts in preferences - they are in place. I got Blender 2.62. Please help.

Have you first selected the edges you want to cut and are dragging the LMB ?

Yes, I’ve tried selecting them all and selecting individual edges, I’ve dragged LMB all around, but it only 3d cursor that moves (not from dragging, from initial click).

Now i have discovered something unusual: in text editor - i press and hold any key and it goes like this - ssssssssssssss, all except k why can it be?

Crappy keyboard ?
Toast crumbs under the K key ?
Try another keyboard ?
Does the K work in other applications ?
Close blender, reopen, reset to factory defaults (File / Load Factory Settings), try again

No crumbs, no sir. Good keyboard it is jus holding k doesn’t work. As you may see I can type normally k when i press once, but holding it doesnt seem to get that signal that it is being held. Weird. Well I guess its not blender anyway. If I find solution I’ll post it here - maybe it will be useful for someone.

Well, since in BIOS setup I had same problem I considered this was a keyboard mulfunction. I’ve change it and now Blender’s knife works just fine. Thanks for your time.