If a user expands the chatbox's height, this occurs:
Not the only one who managed to reproduce this bug. Using Chrome 23.0.1271.97 on Windows 8 x64.
This is an issue of non-matching heights between the textarea and the CSS. On the element itself, a height of 58px is specified (which becomes 62px with the padding added in), which is exactly the height of the section being used in the sprite image. However, the CSS specifies a
It should show on all browsers which properly implemented everything. If not, you probably have the sprite image blocked or something, or your browser sucks.
Anyways, having the same max-height in the CSS as the inline height so you can't expand it vertically seems like the intended behavior. Simple enough fix. :P
I have just removed the background image for the next build. It's 2013; there's no reason to use an image to give the box a subtle inset box shadow anymore.