I am having worse WiFi issues than with 10.5.1. I decided to completely re-format and load Leopard on my Macbook. I can get onto the wireless network and download 10.5.2. Once 10.5.2 is installed and the system is rebooted, I cannot connect wireless with my network even though I get the "full bars". If I connect my other wireless router (FON), I can connect to the internet. I am suspect there is some incompatibility between my main router (DLink 625) and Leopard. I may have to get a Linksys router. Does anyone else have similar problems with a DLink router???