I ran into the same issue. I have a Sanyo and TLC Roku TVs and they both had this issue. Rescanned a few times and it appears the information is back on but there is a delay in the display. I also no longer have the "icons" of each channel in the guide (Peacock feathers on NBC, CBS Eye, etc). The guide now only shows the channel number.
Other Roku users have reported that changing the zipcode and then rescanning for channels resolved their issue. We would recommend trying that troubleshooting step and keeping us posted what you find out.
You can change the name and icon of any of your TV's inputs, or hide inputs you don't use so their tiles don't show with your other inputs on the main menu. Go to settings -> Inputs and make any changes to each of the input names or icons you want, and hide inputs you don't use.