[CentOS] Yum metadata / CR problems

Hi, after the release of 6.1 I have to do a "yum clean all" on all my 6.0 machines in order to make yum work again. The reason is that the old CR directory on the mirrors is now empty and the new one isn't used until I actually upgrade the system to 6.1 (or at least the centos-release package).

Isn't there a better way to handle this without breaking yum?

I'm also not quite sure why the "yum clean all" is required. It has been a few days now since 6.1 has been released so shouldn't the cached metadata have been expired by now anyway or is there metadata that has unusually long caching times?

Regards, Dennis