Problem with https and git-pull

I'm finding that git-pull using https does not work in the way I would expect.

I created a bare repository, test.git, available by https://

I then cloned it:

% git-clone https://host/git/test.git

So far, so good.

Then I made a change in a different clone and pushed it.

When I next did git-pull it just said:

% git-pull Fetching refs/heads/master from https://host/git/test.git using https Already up-to-date.

But it *isn't* up-to-date! If I do the same exercise with git:// or ssh:// on the same repo then it pulls down my changes as expected.

Tried with:
   git version 1.5.3.4 (debian testing)
   git 1.5.3.5-dirty

curl is 7.16.4

The server access log shows the git-pull happening, and there are no errors reported by the server.

Is there something obvious I'm missing?

Thanks Luke