At the time you made the dump your PS3 was booting from ROS0 (with 4.82 OFW + ps3exploit patch). And the ROS1 (marked as unkown) was inactive
Now that you have installed ferrox 4.82 the data on ROS1 has been updated. Now your PS3 boots from ROS1, and ROS0 (with 4.82 OFW + ps3exploit patch) is inactive and has not been modifyed
If you install ferrox 4.82 again the ROS0 will be updated (and your PS3 will boot from ROS0), so both ROS0 and ROS1 will have the data from ferrox 4.82
Not needed to do this though... most probably at some point you will install another different CFW, so the inactive ROS will be used, and so on... every firmware installation is made on the "inactive" ROS
As a resume in simple words, everytime you install a PS3 firmware it happens something like this:
step 1 ) install firmware to "inactive ROS"
step 2 ) switch "inactive ROS" flag to "active"
step 3 ) switch "active ROS" flag to "inactive"
step 4 ) reboot