DirecTV's receivers have supported Macrovision on the analog outputs since the beginning; this is a requirement of the content providers. It is up to these providers to choose when to enable Macrovision; it can be done for a whole channel or just for a specific show. Your DVD recorder is recognizing the Macrovision encoding and doing what it's supposed to do: giving you the error.
As to why this just started happening, who knows?
You can try rebooting both devices, but otherwise, it's up to the content providers.