I have OM working on a 2950 with a PERC/5i card. You can't use OM 5.5, you have to use 6.1. I did run into a problem with one where I had installed OM 5.5 first. You need to make sure you completely uninstall all components and make sure none of the RPMs are installed. I ran the uninstall for 6.1, then for 5.5, then did the following.
rpm -qa|grep srvadmin
Then run rpm -e srvadmin-package name
Then try to reinstall 6.1 using ./srvadmin-install -x from the supportscripts directory.
Hope that works for you.