Horde problems

Hi,

I installed Horde with all other pakedges from the install scrips meny. Now, only Horde as core is functional, nothing else. I'm getting this message:

Some of Forwards's configuration files are missing or unreadable
conf.php
This is the main Forwards configuration file. Generate it by going to the Configuration Web Interface.

Create these files from their .dist versions in /home/postmaster/public_html/horde/forwards/config and change them according to your needs.

then when I'm getting to configuration pages this error message appears:

A fatal error has occurred
You need the domxml or dom PHP extension to use the configuration tool.
[line 26 of /home/postmaster/public_html/horde/admin/setup/config.php]

When domxml & dom PHP was installed manually with YUM,
my apache crashed, so I had hard time to bring it to normall state sone as this is production server...

thanks...

J.