I noticed this too about a week or so ago.
There is an easier way to get the VOTE button back without having to go back through the artist gallery or back to the Bryce gal.

When you open an image from the Hot 20 section, the URL in your browsers Address bar will look something like this:

http://www.renderosity.com/viewed.ez?galleryid=771704&Hot=Y&Sectionid=2

To get the VOTE button in your current window, just delete the part of the URL from &Hot... on (the text I underlined). Then just hit enter (or the GO button in IE). The page will reload and the Vote button will be there.

Anyway, thats how I do it. I am on dial up, so going back through the galleries takes me some time. This saves me all the trouble.
-Bruce