A bug that has been an issue for over two weeks now, is still an issue. The bug, first reported at Google AdSense Help forums explains that when some publishers try to change an existing channel, it simply does not work. The bug has been confirmed to be an issue in both Internet Explorer and Firefox.
The bug was first reported on July 26th and acknowledged by AdSensePro Jennifer two days later, where Jennifer said:
Thanks for bringing this to our attention. I'll take a look.
But since then, even after fifty-plus posts/complaints later, no one has fixed the issue or given an update on the status of the fix for the issue.
I am not sure how critical modifying channel names are for publishers, I assume not that critical, but there are quiet a few complaints on this issue and it does warrant a response.
Forum discussion at Google AdSense Help.