Please see this site: www.herbalspan.co.uk
The site is running Magento 188.8.131.52 with Magento’s modern skin.
The thumbnail images under media/catalog/product/cache have already has the black frame, which means Magento generated the thumbnails and added the black frame.
Apparently it is not CSS as I did not touch anything.
I think it happens when I moved to an VPS hosting a few days ago, as the other site in this VPS which was intalled as Magento demo site also has same problem. You can see the image in the middle in this link: http://www.hottoy.co.uk/catalog/category/view/s/hard-drives/id/29/
My feeling is I didn’t setup PHP correctly or miss any module?
Any suggestion and comment and help please?