Not sure if you intended to go back and insert different CSS for...

div.itemMainImageBlock span.itemMainImage

...than what you have for...

div.itemImageMainBlock span.itemImage

...or if you just got the words mixed up but the first set of CSS information is in the code but doesn't have values in the CSS. I have added it to my CSS but wanted to let you know so you could change either the PHP or CSS for the next release.