The drpadmin calls the /etc/conf/bin/idmkinit program in SCO.
This is the same call when rebuilding the kernel, and it asks whether you "Would like the environment rebuilt".
This will remove the current /etc/inittab file, and rebuild it from the files in /etc/conf/init.d/* directory.
This would indicate the inittab file was changed, while the /etc/conf/init.d/drp file was not, causing the changes to disappear.
For example, when a tty is enabled from the command line (enable ttyx##), you will notice it respond with information that the /etc/inittab and the /etc/conf/init.d/drp files have been updated. To resolve this, be sure to perform the same changes in the /etc/conf/init.d/drp file to match those settings changed in the /etc/inittab file.