MD5 mismatch on my 12.04 ISO, what is going on?

Solution 1:

So, firstly, sorry for the confusion here. Fundamentally it came down to a communication glitch between the release team and our sysadmins.

Around release time, we push many of our images out to Amazon's CloudFront service to keep our bandwidth use under control. releases.ubuntu.com is managed directly by the release team, but the images on CloudFront are pushed by our sysadmins, and we have to push there well in advance to make sure everything's in place. The sysadmins pushed the most recent daily build at the time, but after that we had to respin images for some serious bugs, and we forgot to let the sysadmins know about this so that they could update CloudFront. As a result, you were getting out-of-date versions.

We've pushed updated images to CloudFront now, and all should be well, although I'm going to check things over manually just to make sure.

Solution 2:

Trust the md5 and not the size. My download matches your size and the md5 has from the site as well.