YUM updates/primary_db dismally slow

I've searched for threads regarding the slowness of yum and it seems to be a common problem.

None of the fixes seem to fix my issue though, and it's only slow when refreshing updates/primary_db - all the others update at full speed.

I can also download from the servers directly without any problem.

I am using fastest-mirror plugin and did a yum clean all. Still slow (sub 10kB/s).

Any advice?