SOLVED: Private channel - tries to update, but fails every time.
I had a problem with a private channel not updating. I finally figured it out, so I'm updating this post with the resolution just in case it helps someone else out.
The only changes made to the private channel were graphic in nature -- splash images, display icons, menu overhang graphics, etc.
Turns out, on those display graphics (which shows the channel graphic in the overall ROKU menu -- like a channel store icon) you really need to make sure your graphics are pixel-perfect. Supply a graphic that isn't the EXACT size asked for, and the channel will refuse to update.