I've had the problem at home, which is Cox, and at work, which is Nuvox. Problem happens with both IE and Firefox. I'll grab some ss next time it happens and email them to you, Miros.
I was originally hoping the DNS issues would sort themselves out as the various ISP's DNS servers synced up and downloaded the changes.
I truly am baffled about the problem as it should have resolved itself by now.
I am planning on switching the DNS to something like open dns or maybe use the domain name providers DNS services. I'm currently looking at how to do this with minimal impact.
This still happens every few days for me. In the past two days I haven't been able to use a regular qcdn link at all, even Firefox has labelled QCDN in the Recent Activity bar as "Problem Loading Page" instead of "Quetzacoatl Daily News."