What you don't want to do us upload an update to an existing app signed with a new genkey. So cancel those submissions. Download the existing published package and use that to rekey your device with the password you used previously to running genkey.
You always want to use the same key for an app, this will preserve all information the app stores between versions - otherwise you are looking at wiping out any links, bookmarks, favorites etc once the channel update goes live.
- Joel