createdb argument question

For some odd reason, Rails decided to call createdb as:

createdb foo_database -E utf8

On my Mac systems, this work.  On my AIX system it does not.  I get:

createdb dog -E utf8
createdb: too many command-line arguments (first is "utf8")
Try "createdb --help" for more information.

Has anyone else bumped in to this?  Is putting the arguments after  
the database name known to work?  Looking at the code, it seems  
rather magical that it works but I just looked at the main routine in  
createdb.c and not the routines it calls.

Thank you for your help,
Perry