I'm new to Lightroom -- I installed the 4 beta and am liking it quite a bit, but I'm having trouble with gamma shifts when exporting images. When I export the image, my blacks get completely crunched -- it doesn't match Lightroom at all. It's not just the JPEG being displayed wrong -- I've looked at the exported image on a few different computers and they always appear crunched.

My monitor is calibrated (using an X-rite i1 Display 2), and I re-calibrated it yesterday to make sure that isn't the issue -- it made no difference. I made an image to demonstrate the problem:

Does anyone know what would cause this?