This site seems to be fine in all sites except for IE 6 - 8. It is also ok in IE9+. However in IE 7 and 8 the pages showing thumb over images have the background infront of the images.
I have fiddled with the html and looked at the html validator but to know avail. If anyone has any thoughts i'd be really grateful!
The link to one of the offending pages is http://www.englishoakframes.com/porches.