I have an iMac connected to my router via WiFi, and a PC connected by ethernet to the iMac. The iMac is sharing its connection. I've never had a problem with this in the past (pre Lion anyway) but now all web page requests take an eon to resolve on the iMac (they are instant on the PC). It suggests to me the iMac is attempting to resolve it through the PC first every time? I've tried reordering the connections in the network settings but that made no difference.