[CentOS] Installing Skype in CentOS (4.4)

I'm trying to install Skype on a CentOS 4.4 system and I've followed the
instructions on the Skype website at
http://www.skype.com/download/skype/linux/repositories.html
but when I run yum install skype it fails with a whole string of error
messages, ending with 
Error: failure: RPMS/libsigc++20-2.0.17-1.el4.rf.i386.rpm from rpmforge:
[Errno 256] No more mirrors to try.

Has anybody managed to install skype successfully - if so, how please?

Thanks,
Andy