nnimap and multiple accounts on the same server

[Tommy Kelly <tommy.kelly@verilab.com>]

I have a personal gmail account and one under Google Apps. I'd like to
read both with nnimap in Gnus. There's a heap of advice on this on
google but nothing I can get to work sensibly. What I have at the moment
is the simplest setup involving both my .gnus and .authinfo: 

In my .gnus:

(setq gnus-secondary-select-methods
      '(
	(nnimap "work"
		(nnimap-stream ssl)
		(nnimap-address "imap.gmail.com")
		(nnimap-server-port 993)
		)
	(nnimap "personal"
		(nnimap-stream ssl)
		(nnimap-address "imap.gmail.com")
		(nnimap-server-port 993)
		)
	)
      )

And in my .authinfo:

machine work     login me@mydomain.com password my_gapps_password port 993
machine personal login me@gmail.com    password my_gmail_password port 993

That's based on my reading[1] that the current authentication mechanism
allows the machines to be described in .authinfo using the identifier
(in my case "work" or "personal") instead of the actual server itself
(in my case "imap.gmail.com").

HOWEVER, the above doesn't work. When I run gnus it acts as if it cannot
find the authentication info and prompts me for logins and passwords. If
I provide them, I get access to the two accounts just fine. But I'd like
to have it authenticate automatically.

I know the authentication works if I replace "work" or "personal" with
"imap.gmail.com" but of course then I can't have the two separate
accounts since they're both on the same server.

Any help appreciated.

thanks,
Tommy

[1] e.g. here http://josefsson.org/nnimap/nnimap.html#SEC29