BUG: Accessibility: click hint on "Enter giveaway", "Create Ticket" etc

There's an issue with the "Enter Giveaway", "Remove Entry" and "Create Ticket"
buttons. They seem to be lacking a certain hint, informing the browser they are
clickable.

Whatever it is that's missing, it causes pentadactyl[1] (and I assume screen
readers and other accessibility software etc) to not know they are clickable.
This requires me to access and use a mouse for them.

Unfortunately I am unaware of the actual hint required in the
HTML/JS/CSS. Traditionally these would be <input type=button> or similar but
that's probably web 1.0 these days :P Does anyone know off hand what might be
missing?

[1] Pentadactyl - a browser plugin that allows for complete mouseless keyboard
navigation, similar to vimium, vimperator etc