Using tramp from Cygwin Emacs

[KARR, DAVID (ATTCINW)]

I'm attempting to get tramp working from my Cygwin Emacs (23.0.92) to a
Unix box.  I've looked at various hints for this, but I still can't get
it working.

I have no trouble connecting to the box using putty.  I set my
"tramp-default-method" to "pscp", as suggested in at least one place.
When I pressed Enter on the "/host:path" value, it hung essentially
forever.  I looked at running processes, and I saw it trying to run
"plink", which was hanging.  I tried running that command line directly
from the shell, and after giving me the "login as" and "Password"
prompts, it printed the system welcome messages and then said "Access
denied" twice and redisplayed the password prompt.

Any ideas how to get this working?