The posgresql backend tries to identify the inexistence
of the "schema" table by using it and catching the
subsecuent exception, matching the error message string
with the standard _english_ error message: '"schema"
does not exist', which is broken when using another
locale (mine is spanish, but google says it was also
broken for other guy wich locale seems to be deutsch [1] ) 

The only sane patch that occurs to me is matching
against a more relaxed literal. Attached is a patch
that simply changes it to 'schema'. It could be broken
and catch another kind of exceptions, but that's not
going to be as harmful as the current behaviour.

[1]
http://permalink.gmane.org/gmane.comp.bug-tracking.roundup.user/6742