hg update over ssh not working (hg clone works well...)

hg update over ssh not working (hg clone works well...)

I have some code on bitbucket.org under mercurial version control. Now I
want to download the code on my ubuntu machine over ssh. When I use hg
clone everything works well. However hg update never updates any files.
I'm not even asked for my ssh password. I checked these setting:
ssh -v hg@bitbucket.org
-> looks ok.
hg showconfig
-> path.default = ssh://hg@bitbucket.org/user/myrepo...
Do you have any idea what else to check?
Thanks.