Swanny007 - 4:55 pm on Sep 9, 2010 (gmt 0)

CodeJockey, you didn't say how many impressions you were talking about but a 12 hour test is in my opinion not long enough to make a call. There are stats delays almost every day with AdSense. I usually give changes at least 1 week to gauge it's effectiveness, even if it looks bad the first day.