Once you install that panel, then you will have multiple cron entries that try update the clam DB. Jesper's defaults to every 2 hours I believe, and the server-manager panel gives you options on when you want it to update the DB. Jesper's entry is in /etc/cron.d/freshclam.cron, and the entry from pagefault is in /etc/crontab. If you set the server-manager panel to never, it will remove those entries from the crontab file, or you can remove the freshclam.cron file.
That is the only conflict I have found between the 2 packages.
If you have clamav installed from Jesper's previous script and have the rpm from pagefault installed, then go to upgrade, you will get an error stating,
"Upgrade ClamAV failed - e-smith-antivirus from pagefault.org installed." If you rpm -e that package before you run it, or modify the script to not check for the package and rpm -e, then rpm -Uvh the same package at the end, it should install OK as well. I have the latest script from Jesper's site and the pagefault rpm running together and haven't had any issues to date.
YMMV,
JB