Daily many people get I485 approval in this forum and also many recently approved people still visit this forum. Though the "Job change" issue has been discussed many times, i have given a final detailed (scenario based) advise on the "Job Change after GC" issue. It might help some people. Please see it here :
http://www.immigrationportal.com/showthread.php?p=1024544#post1024544
http://www.immigrationportal.com/showthread.php?p=1024544#post1024544