I moved my website to a different folder and ran the "Velvet Blues Update URLs". After this, all links to images were broken.
When I look at the source of the page, it shows that the plugin has added an extra "http://" to the links. So now they all start with http://http://.
I can figure out how to fix this with a MySQL search & replace, but this is something the developer might want to check out. I ran the plugin on a 3.5 installation.