1. On the "my chumby dashboard" page, choose the channel in the "Select a channel" dropdown
2. Right-click the "manage channel" link and choose "Copy Shortcut" (or "Copy link address" or "Copy link location", depending on your browser)
3. Open notepad or any other text editor and paste the address; it should look like this http://www.chumby.com/widgets/channels/ … 39865EDFEF
4. Replace "channels" in the link with "remove_channel"
5. Copy and paste the modified link into your browser and press ENTER
With any luck, this will delete the channel and you'll wind up back on the "my channels" page with the errant channel removed from the list. I tested my instructions and they deleted the test channel I created; however, I could not reproduce your issue even with the same channel name, so something else may be at play here.
If the tweaked link doesn't get rid of it, you may want to try deleting your browser cache and history (first, close all browser windows but one, and go to a non-chumby site like www.google.com -- this will make sure that the browser doesn't retain anything from the chumby site). After doing so, try logging back into the chumby site and see if the delete control is available, or try the tweaked link again.
If neither of these work, Duane might be able to manually remove the channel from your profile. Let me know whether either of my instructions worked, and if neither did, I'll point Duane your way so he can get in touch with you and hopefully get this resolved