I just thought I'd throw this out there... I've had this issue with every other IPS display I've ever used. I had three 21" HP IPS displays connected to a Mac

I just thought I'd throw this out there... I've had this issue with every other IPS display I've ever used. I had three 21" HP IPS displays connected to a Mac Pro for a few years and all three of them exhibited tho exact same condition. The 23" Apple Cinema Displays we had at my university also did the same thing. I just chock it up to the IPS display technology, and assume all IPS displays do that to some degree. IPS is not known for having particularly great pixel twist times, and thats probably related. That said, I'd still use an IPS display in a heartbeat for the color accuracy. It's truly phenomenal. The after-image is annoying, but I'm happy to trade it for the color accuracy.