My Good Deed

Those of you who have keen eyes have noticed that I've added a new link in my favorite blogs section. I've stumbled upon Aviad's blog this week when I've encountered a problem while upgrading my EBS database to 10g. Actually that's the second time I encounter this blog, the first time was when Steven Chan mentioned it in his "Notable Apps Blogs" list. This first time I was just proud to see an Israeli in Steven's list and didn't linger too much in the blog (although it did strike me as quite an impressive blog).
The second time, even after I've discovered the specific problem I had on my hands wasn't mentioned in the blog (although many others were), I did some more thorough browsing. The guy really does excellent job, his blog might have saved me a lot of time if I was aware of it before.
Anyway, this blog inspired me to stop complaining for at least one post and share some useful information, the issue I had looks like a good place to start.

As mentioned, I'm in the process of upgrading my EBS(11i) database from a 9.2.0.5 database to a 10.2.0.3 database. During the upgrade phase (after the database software is already installed) I've encountered an "ORA-12631: Username retrieval failed" error message. The problem, apparently, was that I didn't have a listener up and running. Having a listener up might seem very basic to some of you, but I was working with my own upgrade notes that were compiled based two successful upgrades. More than that, DBUA starts the database on its own and I'm pretty sure it did the same thing with the listener on my previous attempts. I don't really know what was wrong this time but I did get back to the original notes by Oracle to see if I might have misinterpreted something.
There's definitely some confusion here: Note 362203.1 (EBS upgrade note) orders the stopping of any existent listener while the database upgrade document (not EBS related) mentions the need to create a new listener using NetCA if I don't already have a listener. So, does the upgrade manual mean I should have some listener up? And if so, why does the EBS note tells me to stop all listeners?
Again, if the stopped listener was indeed the issue, I'm sure there was some more sophisticated way to phrase the error message.

Well, had some bitterness in my post after all.
At least this might be useful to someone.