Spacing different in stage and publish -- help me figure out why!

Here's what my project slide looks like in Stage (the two yellow lines framing the slide are part of the Master Slide -- I drew red arrows on the area I'm having trouble with):

Here's what it looks like in both the preview and published file:

As you can see, there is a significant gap on the published/preview version which does not exist in the stage.  This is happening on all of my slides and I can't figure out why.  Anyone have any ideas to help me fix this?