I appreciate your help but I don't think you're reading the entire problem.
Fine - then assume I don't know what I'm talking about, didn't have the exact same problem and didn't fix it myself. I've given you the solutions, if you can't take the problem into your own hands and follow the given advice, then I can't help you - we can't magically fix your computer for you remotely.
If you don't understand exactly what to do, then it would make sense to post and ask for clarification, rather than telling the people who are trying to help you (and plenty of others) out that we don't know what we are talking about.
The second problem I get now is this message "Can't find DAE folder in system folder
(-9064) I did not move or delete anything. It started after I started GB for the first time
after the second complete install.
The DAE is the ProTools driver (Digidesign Audio Engine), so it looks like you might have turned that on for some reason. Go to your audio prefs and see whether the ProTools drivers (DAE) are turned on, and if so, turn them off.
And that's nothing to do with the missing content problem.
When you say install again, do you mean re-install everything. This is the generic
direction I've gotten from Apple. Frankly I'm tired of re-installing everything
because it takes hours.
Well, it may take hours, but if you'd done it already you would probably have fixed it days ago, and not be spending any more time posting about it.
I said the way
I fixed it was to use Pacifist to extract the
instrument content (not the loop content) only to a second place, so I could see what content I should have, and move the missing stuff to my library automatically. If you have the skills to do that, that's what I recommend doing, and it should take a lot less time than reinstalling the entire content. Remember, the issue is only with the instrument content, not the loop content.
I do not only use LP8. Someone out there must have a clear explanation of what's wrong.
The Logic installer has a problem which means it deletes some existing GB content with confilcting names. This manifests itself when you have Garageband content from older versions (and is why iLife 08 also fixes it, because it has newer content).
If this is one of the most common threads as you say than why is Apple not addressing
it with a patch or an update.
I cannot speak for Apple. Maybe they've already fixed it. Maybe it's not the most important issue they are dealing with. Who knows? They are certainly aware of the issue, which is why they issued a tech note.
Must I delete everything LP8 before re-install, or does it matter?
No.
Do I have to re-install the O.S. too?
You're being a bit silly now, you don't need to reinstall OSX. This is a Logic content issue only.
In any case, perhaps you're willing to listen to someone else - I try to help out, but I'm not going to fight to help people who don't want it, so I'm out. If you are really stuck, a bit of research will give you many answers. In any case, I hope you get it sorted, and I'm sorry I couldn't fix you issue in a way that you deem acceptable...