Change Bundle Seed ID, same Bundle ID for upgrade

I asked a similar question earlier (https://stackoverflow.com/questions/4553741/clashing-app-id-that-needs-removing), but perhaps I can ask a different way:

Am I able to update an existing application in the App Store by changing the bundle Seed ID, but keeping the bundle ID the same?

ie, going from:

DFG5TY7E3.com.domain.appName

To:

HGERF562D.com.domain.appName

Does this cause any problems? I know that if I change the bundle ID (com.domain.appName) it will not upgrade, but not sure on the bundle seed id (DFG5TY7E3). See the link above for a full explanation as to why I need to do this...

So I have spoken to Apple today via the phone. They have suggested the following:

I can use a new Bundle Seed ID as long as I am not using the device Keychain in my app (whatever that is?)

The quote this article:

Note: If you are using the device Keychain in your application, be sure to select the same Bundle Seed ID that you used for your other applications from the Bundle Seed ID pop-up menu.

From: http://developer.apple.com/library/ios/#qa/qa2009/qa1680.html

From that they summised that it is not necessary for me to use the same bundle seed ID. I will test this and let you know before I mark this as answered.

You can't do this. The seed is actually part of the bundle ID. DFG5TY7E3.com.domain.appName is a totally different bundle than HGERF562D.com.domain.appName.

So, can I change the bundle seed id for an App Store app?