Thanks for the reply, Joel.
This is, in fact, a private channel. When I sideload the app onto my Roku box, it correctly uses the new image in "My Channels" on the box. However, when I package up that release and publish it, the old image is used. I know that the newly packaged app has been successfully published because the changes inside the app itself do show up in the newly published app.
When I go to channel properties on owner.roku.com, I do not see any way to modify or replace the existing images. Under channel details, I see links for the HD and SD images, and they are the old ones (not the one displayed in my channels on my roku for the sideloaded version). Under edit channel, I can select a new package, but not new channel posters.
Any additional ideas or suggestions?
Thanks,
Jon