I recently upgraded from 4.1 to 5.1, I set up some virtual domains and mapped them to I-bays the sites where working ok until the upgrade then after I was getting password prompts whenever a page was loaded. I found the problem to be my Images stored under /common/images I had to rename this folder and change every page that made referance to it! I was able to delete the \common folder and still type my site in with /common and recieve the password prompt??? Where is this /common coming from??