git rebase behaviour changed?

Hi,

git-rebase was a very useful tool for me to help organize my patches.

Recently, it seems the behaviour of git-rebase changed.  It used to take 
the commits I'd made to my "master" branch and reapply them to a new 
"master" branch on top of "origin".  Where rebase from git-0.99.x used 
to work, git-1.1.3 now does nothing and gives me the following message:

git-rebase origin
-> Current branch refs/heads/master is up to date.

However, I can do the "rebase" manually with:

git branch master-20060117
git reset --hard origin
git-format-patch -k --stdout --full-index origin master-20060117 | \
	git am --binary -3 -k

Is this broken, or am I meant to be doing something different now?

thanks,

Mike