Cheney's Access to President Limited?

Insight reports the Vice President's influence is waning with POTUS. $Q: Over the last two months Mr. Cheney has been granted decreasing access to the Oval Office, the sources said on the condition of anonymity. Have to take this one with a grain of salt—it seems incredible that Cheney would have any access problems at the Oval Office. Assuming it's true, whose job is it to tell Cheney not to come around so often?