Install 4.0 on 3.0

[Chuck DeCarlucci]

Dear Mr. McDonald,

I searched all over the YDL website looking for info on installing 4.0 
over top
of 3.0. The search came up with 1 good hit that promised an answer:

... will want to know whether they can install YDL 4.0 over YDL 3.0.1 
without ...
for significant questions whose answers might help other Yellow Dog 
Linux users,
we ...

Reading the entire email I got to the punch line: "...we won't know 
until someone
does that experiment."

The full paragraph reads:

"Similarly, soon a lot of people will want to know whether they can 
install YDL
4.0 over YDL 3.0.1 without losing user data. Well, we won't know until 
someone
does that experiment."

I am about ready to try that experiment but would sure like to know in the
intervening 6 months since the email "FAQ Creation" dated June 30
Clint McDonald to Chris White was written if anyone has come up with an 
answer.

Have there been many reports one way or the other regarding a YDL 4.0 
install
over top of a 3.0 system without losing user data?

I am posting a question to the Install Forum - but find it very strange 
that neither the FAQs
nor the User Forum have a discussion of this issue. The Install manual,
ydl4.0_guide-double.pdf, is also silent on this issue.

Respectfully,
Chuck DeCarlucci