up2date x86_64

[fedora linux]

I'm quite frustrated here.

I have three i386 systems, and am helping a friend with his x86_64.

With FC1, I modified my /etc/sysconfig/rhn/sources file to allow for
mirrors, and everything worked well.

But now I am using FC2.  When FC2 came out there was a notice that the
modifying of sources files was not strictly necessary, since up2date
would go through a round-robin procedure to find an available server. 
For the i386 system, up2date seems to work.  I have no trouble
upgrading it.

For the x86_64 system though, u2date no longer seems to work.  It
worked since June, but not anymore.  No matter which server it is
looking at, it seems to hang.  I tried yum update also, but it also
does nothing.  Should I just edit the sources file, or are the servers
having a bad week?