Problem using TRAMP with zsh

[pluskid]

Hello everyone! I have problem using TRAMP. When my login shell is
bash, I can use it happily. But when I change my login shell to zsh
these days, Emacs hangs when I'm trying to open file with `sudo'
method using TRAMP. I find that it is because the zsh prints extra `#'
or `%' that TRAMP hangs when connecting to it with `ssh' method, just
set this in zsh's init file will fix this:

setopt No_prompt_cr
setopt No_prompt_sp

But I don't know what's wrong with the `sudo' method. Even the `su'
method is fine. It just hangs when "Tramp: Waiting 30s for remote
`/bin/sh' to come up..." I don't know how TRAMP implement sudo method
or how it differs from su method. Can anybody tell me how to fix this?
Thanks!

BTW: I'm using GNU Emacs 23.0.0.4 (i686-pc-linux-gnu, GTK+
Version 2.8.18) of 2006-08-14 on kid and TRAMP 2.1.5 on Debian sid.
And the version of zsh is zsh 4.3.2-dev-1 (i686-pc-linux-gnu)