If you have a layer which has the css property height: inherit; and also a repeating background image, you might find yourself lost with opera. You try and try so hard but you can't get the background work. You might want to delete the height: inherit; property and eventually everything works fine. This may happens, when you use floating layouts. This applies even so, if you have no height defined for the parent div container.
It took me about 30 minutes to figure this out.
I didn't needed the height property and so I am lucky :)