I've just upgraded from SB2.0 to SB2.1 and got some errors you might be interested to know.

I followed the rules found at the release notes at http://download1.sw-soft.com/SiteBuilder/2.1.0/Sitebuilder-2.1.0-rh9.build050915.20.txt

The command rpm -Uhv Sitebuilder-2.1.0-rh9.build050915.20.i386.rpm
didn't work for me so I've use one suggestion provided on one of other threads:

rpm -Uhv *.rpm –force

This worked fine for me.

Please have in mind the default db user name and password. After the installation is done and you open your entry point page you get the upgrade db information, but there is no db password and the user might be another.

In case it helps, please let me know.

Now I will to install some modules. If any issues appears, I'll post them here.