connecting with tramp and plink to a non standard port fails

[lmunro]

Hello,
I'm having trouble connecting to a linux server using tramp on windows
XP with plink.
I can connect fine to servers using the standard ssh port but can't
get plink to use a different port using tramp.

On it's own plink seems to work fine. If I open a cmd.exe window and
type
> plink -l user host.example.com -P 55
I can connect just fine using a password or a private key.

But in emacs if I try this:
(C-x C-f)
/user@host.example.com#55:~user/file

The connection fails and emacs complain this way in the minibuffer:
plink: unknown option "-p"
Process *tramp/plink user@host.example.com#55* exited abnormally with
code 1

I have stuck this line in my .emacs:
(setq tramp-default-method "plink")

Anyone has any idea why?

I've never had any problem connecting to this server with tramp on my
mac (using ssh and port specified in ~.ssh/config), so I know it's
possible...

Much obliged for any help.
LM