The last problem is in the 9th row (.../zp-core/setup.php )
"...
zp-config.php file
? Strict permissions [is not in effect]
MySQL
..."

How to solve this?

Thank You!!

There should have been a warning box message along with this that included a link to check to set strict permissions. You can probably ignore this for now, although the security is lessened.

Yes, there is.

"Warning!
...
Click here to use strict file/folder permissions.

NOTE: This option ..."

But the click on "here" happens nothing. The page doesn't change.

Have you completed the MySQL parameters part--that is, is there still a form for the user name, etc.?

What does the link for the click here read? Does the page reload when you click it?

The MySQL part is OK. Username, password, name of the database.

The page is reload, but it remains pink, not green. I have seen on another page.
I have read, that Ubuntu 8.04 does make the permissions different, then the older versions. ?

Wenn I click on 'Go!', the application is running, but I can't open the new created album (HTML error 404 [maybe Apache problem?]), and the "current thumbnail" doesn' exist, or it is empty.

I don't know anything about Ubuntu, but did you check modrewrite and the .htaccess file?

What must I check?

If you uploaded the .htaccess file, the option for modrewrite and if your server supports that at all (setup actually should tell about that).

"
RewriteEngine On
...."

I think, this is OK.

I must install Apache2 rewrite module, and so it runs.
ubuntu:
"sudo a2enmod rewrite"