[SOLVED] Extra space next to images when caption text is centered

My website is http://carolynapappas.com/

I am having a problem where it is adding extra space to the left of an image when the image caption text is centered. If I align caption text to the right, it also gets screwed up. This only seems to be apparent when the image is small, as in the second image on the page. When I align the caption text to the left, the white space goes away.

Do you know how I can delete this extra space? I have driven myself crazy trying to find it. Thanks!