Gallery Breaking

My galleries on my WordPress are displaying wrong. There is a large space between the first and second row. After that, the gallery displays fine. What can I do to solve this?

http://www.thecatholichighschool.org/news2/news/fatherdaughter-dance/

EDIT: I just checked IE7, and it displays fine there. It does not display correct in IE6 or Firefox.

Thanks.