extra space added to Module Class Suffix on Custom HTML

Hello,

I'm working with the T3/BS3 install for the first time, and I noticed my custom.css wasn't being applied to the Custom HTML module I had made. On inspection with Firebug I noticed an extra space space in the class. So instead of reading

"t3-module module-rectangle"

Firebug is showing

"t3-module module-rectangle "

(see attached image)
Does the extra space at the end explain why my css isn't working? I am assuming there's an error in one of the joomla/T3 php files that's adding the space. Anyone have thoughts on which file it might be? I'll do some digging and post the solution if I can find it, You should keep an eye on your suffix if you're doing any Custom HTML module styling.

Thanks!