In IOS 5.1, the camera button in the lock screen does not work.

This is an iPhone 4 that I upgraded to 5.1 from 5.0.1. The camera button now appears on the lcok scree without havign to double press the home buttn. But when I touch the camera icon, the lock screen brieflyslides upward about 1/4 inch but immediately goes back to the lock screen.

The camera button worked correctly under 5.0.1. I do have a security apsscode set and have a custom lock screen image with ICE information.