Unable to update Webmin

I'm getting this upon trying to update Webmin on my CentOS 6 server:

Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: centos.mirror.transip.nl * epel: ftp.nluug.nl * extras: centos.mirror.transip.nl * updates: centos.mirror.transip.nl Resolving Dependencies --> Running transaction check ---> Package webmin.noarch 0:1.850-1 will be updated ---> Package webmin.noarch 0:1.851-1 will be an update http://GPL:GPL@software.virtualmin.com/gpl/universal/repodata/cf4aa549b7... [Errno 14] HTTP Error 404 - Not Found Trying other mirror.

Any ideas on how to work around this?