I had a similar problem, this may help...
have a look at the html editor instance on the page and find the line
$CKEditor_config["skin"] =
When I did the update, i had the same problem, and found the existing instances I had of html editor used the 'kama' skin, but when I downloaded the update, I only had the 'moono' skin in my folder.
I have sinced changed all instances on the site I was working on to moono as I liked it better.