All links shifted down a few pixels while adding new content. FFox

Hello, me again.

I've been creating content using your theme when something strange happened. I was creating a menu that this occurred. I wasn't messing with template files or css. I'm not sure exactly when it happened, but it seems that every link on the page has shifted down a few pixels. This is only visible in Firefox, but not IE? See attached. If you'd like, I can send you any css or template files if you think that will help. I've edited the CSS, but that was long before any of this appeared.

See attached image.