I have not had any renderosity display problems. Beware being linked to a hijacked site!
Try going into renderosity fresh, typing in their address from scratch and see if the problem repeats. IE7 might being recognizing the IP address as something not-renderosity, even though it displays as Renderosity on your screen. Thieves do this to get your info (and $). They then forward valid messages from the stolen site on to the victim, so there is a time delay before they know anything is wrong.