Hi loralai
This indicates, that jOpenSim did not find the host in it's table #__opensim_search_hostsregister. The result is basically just, that the search data wont get updated. So it is for sure not something wanted, but nothing that can prevent OpenSim or jOpenSim from working.
The registering is usually done during startup of the simulator. For this to happen, you need to have the following line in section [DataSnapshot] of your OpenSim.ini:
data_services="http://url-to-your-joomla/components/com_opensim/registersearch.php"
After the simulator has started up and successfully registered with jOpenSim(Search), you should see a new record with the IP your simulator in this table.
Greetz
FoTo50