This is a discussion on Ref. Code S0a00 within the Comcast forums, part of the Cable and Satellite Providers category.
According to this thread, you're probably experiencing poor signal quality at your cable outlet. Try disconnecting your cable and checking it for loose connectors or even replacing the cable and plugging it back in. Try power cycling your Comcast set top box too.
EDIT: After re reading the original post if all your channels are having that message come up it might be a service issue so you probably should give them a call if you haven't fixed it yet.
Last edited by digitalamps; 11-04-2012 at 09:29 PM.