I dont think \"Joomla <-> OpenSim\" would solve that. It is quite difficult to reproduce that error, but I have some possibilities that I think of and need some excessive testing. All I need is a little time to figure that out.
I also think that the array_merge warning has nothing to do with the map problem concerning the memory message. I already asked, but do you have any phpMyAdmin or so and can paste here the content of the table \"regions\"? Specially the columns \"locX\" and \"locY\" I\'ld be interested in.
Also what is that part of your OpenSim.ini telling:
; ##
; ## WORLD MAP
; ##
WorldMapModule = \"WorldMap\"
MapImageModule = \"MapImageModule\"
... or are they still commented out?
Greetz
FoTo50