Yeah locals will vary from state to state market to market. Most time it's locals issues will be on the channels end. Might call your local CBS station see whats up some come in better than others.
Have you guys scanned to see if the local CBS has a sub channel added for March Madness? I know a few will multicast 1 or 2 matches in the subs, and even multicast the 4th on another local channel.