Which is what causes the effect.. The only thing that you've added is the JKPanel script, and if it's not that the only other thing is jQuery itself, which I doubt, so remove the script if it still produces that result, then maybe look into the code (Which I've done, but I don't see anything out of the ordinary).
If that still doesn't work, and you're looking for a quick fix maybe attempt to set the setting yourself via both CSS then jQuery - this isn't what I'll deem a fix, but it's a solution. The weirdest thing about this is, if jQuery is adding some CSS to it, I would see the inline style, but I don't see it. It's definitely a weird case.
If all else fails, maybe look into getting another script, sorry I couldn't help anymore.