Trouble between Lauren & Audrina?

Why can't LC keep a best friend?

THINGS between "The Hills" stars Lauren Conrad and Audrina Patridge may not be as chummy as they look on the screen. We hear that Patridge, who is roomies with Conrad, locks the door to her bedroom when she leaves their LA apartment because "she doesn't trust Lauren," according to one source. Not to mention that Patridge "gets really annoyed at Lauren's cats because they pee on her rug and on her bed." A rep for Patridge said, "This is ridiculous. Audrina loves living with Lauren." (Source: Page Six)