[eluser]OverZealous[/eluser]
After apparently enough caffeine has gotten into my system, I finally found out that the problem IS within DataMapper / DMZ, and, yes, it can be fixed.
Here's the temporary solution: search for and replace 'left' with 'left outer' in the libraries/datamapper.php file.
I'm planning on implementing this anyway, as that is more appropriate syntax (they are synonymous with each other). It should be fully supported across all databases, since LEFT OUTER JOIN is the correct SQL term.
