strange forwarding problem

I have just installed a mailserver using postfix 2.2.11, along with
amavisd and clamav. It works fine but for one user who has a .forward
file in her home directory, this forwards all her mail to her gmail
address and leaves a copy locally:
user@gmail.com
\user
this has always worked in the past, and the man page for forward does
not contradict that, however, the incoming mail has been forwarded to
her gmail fine, but the local copy has just vanished.
Now the setup with amavis and clamav is just fine, the other users
are getting their mail without any problems, so it is not that.
After a lot of messing around, making up a new account, etc, I tried,
as a last resort to reverse the order in the .forward file thus:
\user
user@gmail.com
It worked, but why, and why would it not work the other way round,
which is how I normally do it.
I have also put a .forward in root's home, to send everything here to me,
it is not working, nothing has come through.
This is on FreeBSD 6.2 prerelease
Does anyone have any ideas, have I missed something, this is by no means
my forst postfix server, I have never had any problems like this in
the past.
I can supply config details if necessary, but not till next week,
alas it is not possible to get remote access to this machine.

--
Martin Smith