custom menu button png's

I'm trying to make a set of custom menu buttons based on the Pro LCD Shapeshifter Theme, and I'm using the same size and shape of the original "Simple" buttons, and yet I'm getting a pixel of space in between the back, play & next buttons. It's that way for all states of the play button area. Is there some way to fix this? I tried changing the file type from png32 to png8, and changing the creator from fireworks to preview.... nothing changed. help! e-mail me @ ryan@cloudbust.com if you can help, thanks!