Restored SharePoint site extremely slow after 2010 visual upgrade

This morning I migrated one of the older Contoso sites to my local development virtual machine and did the visual upgrade to 2010 to start working on some new exciting developments only to find the site is dead slow, at first I thought it was my resources, so I restored the site to a different server where all was fine until I did the visual upgrade on it, then experienced the same thing.

I started working like that but got very frustrated very fast and decided to investigate the issue.

I noticed that this happens every time the context changes or the ribbon reloads, it was almost as if the ‘freezed’ along with all other SP functions until it was done loading and then things would be fine again. While staring at this phenomena I saw the Contoso logo was missing till the last second and then only displayed the ugly red cross associated with image not found, frustrated and being pedantic about things like that (not to mention the luck factor) I figured I can just as well quickly fix that first…

And then it all made sense, the image's URL was hardcoded to the old server name. FAIL!!!

I changed it to point to _layouts after which everything was as good as new, so my suspicion is that the ribbon and all associated functionality was being holdup until it timed out trying to reach the server as my VM was not on the domain.