I also got the problem of X in the first image. 

Part of the script as follows,

<?xml version="1.0" encoding="UTF-8"?>
<simpleviewergallery maxImageWidth="640" maxImageHeight="640" textColor="0xFFFFFF" frameColor="0xFFFFFF" frameWidth="20" stagePadding="40" navPadding="40" thumbnailColumns="3" thumbnailRows="6" navPosition="left" vAlign="center" hAlign="center" title="Tailormade Production Gallery" enableRightClickOpen="false" backgroundImagePath="" imagePath="" thumbPath="">
<image>
    <filename>p0001.jpg</filename>
    <caption></caption>   
</image>
<image>
    <filename>p0002.jpg</filename>
    <caption></caption>   
</image>

and I also check that in the images and thumbs folder the name is p0001.jpg but it still show X in the first image.

Can anyone tell me what's wrong with it?

Thanks