I think I replicated your problem, but I had to use a bit of a kludge to do it (so maybe the results aren't reliable). The only MS machine I had to run PuTTY on was a laptop w/o a regular 10-key pad. The only way I could create the problem was to plug in a regular keyboard, and w/o going into all of the gory details, this had a few strange interactions. But with NUM-LOCK on such that the 10-key produced numbers on the command line, in vim (called vi on this installation), the 10-key produced letters plus a little weirdness. Checking "Disble application keypad mode" (Terminal -> Features) in PuTTY made the 10-key behave as expected. See section 4.6.1 of the PuTTY user manual for an explanation.
EDIT: BTW, I tried sshing into the same machine from a Linux box using the openssh client and tried the same thing. There were no problems. So despite what the PuTTY manual says, I really don't know where the fundamental problem lies.
Last edited by blackhole54; 12-09-2006 at 06:19 PM.