It looks to me like you just lost your groove. 290 is really close tho!! I am sure you smell blood.
Only form comment is to once you create your arch is to keep feet still and planted. It seems like you may be losing a touch of tightness if you fidget around.
Great stuff overall Mike. My bench PR is now 285. It's pretty cool to be at the same point these days, and I hope we both progress well in 2013.