Ya, I've had that before (it's not theme specific - it's xpopup). Just recycling usually fixes it. Also, if you're middle clicking with a mousewheel, be sure to keep it steady when you push down. xPopup reacts to the mousewheel moving up/down by scrolling through items. (Funny... I just had the bug just now testing it out. Not sure what causes it. :P )

Glad you're checking out FBLD. I had a lot of fun with that. Just setting up styles, messing with fonts etc was fun. :D