Missing comments

I have been working on a fansite for one of my friends and we’ve been having problems with certain comments disappearing from the page, but still being counted.

For example: http://gohanxtrunks.net/fanart/rating-fanart/g/jhemos/cell-saga-2-2-246/
That page lists two comments, yet only displays one. The one missing is the author’s comment and we’ve had those authors comments disappear on more than just this piece.

We’re using the SexyComments plugin. Might that have something to do with it?