MathType clipboard-to-clipboard transformation works on Windows, fails on OSX

mathtype_mathml.py

# NOTE: Python must be invoked in 32-bit mode for ctypes to read the MathType lib.
# For example (OSX):
#     arch -i386 /usr/bin/python2.6 mathtype_mathml.py
#
import sys
from ctypes import *

def main():
    # On OSX, use the following line instead:
    #    lib = cdll.LoadLibrary('/Library/Frameworks/MT6Lib.framework/MT6Lib')
    lib = windll.LoadLibrary('MT6.dll')
    lib.MTAPIConnect(0, 30)            # mtinitLAUNCH_AS_NEEDED
    
    # Use MathML translation mode
    file = "MathML2 (namespace attr).tdl".encode('utf-8')
    lib.MTXFormSetTranslator(4, file)  # mtxfmTRANSL_INC_MTDEFAULT
            
    # Set source and destination as clipboard
    src = -2          # mtxfmCLIPBOARD
    src_format = 7    # mtxfmTEXT
    dst = -2          # mtxfmCLIPBOARD
    dst_format = 7    # mtxfmTEXT
    
    # Convert (get MathML)
    result = lib.MTXFormEqn(src, src_format, None, 0,
                            dst, dst_format, None, 0,
                            '', None)
    return 0

if __name__ == "__main__":
    sys.exit(main())

pasteboard_types.py

# The following code will print the available pasteboard types. If a MathType
# equation is on the clipboard, you will see 'pict' available. This is what
# I get:
# (
#    "dyn.ah62d4rv4gk8ynynsku",
#    "CorePasteboardFlavorType 0x45514E44",
#    "dyn.ah62d4rv4gk8y4xnqna",
#    "CorePasteboardFlavorType 0x4D4D4C50",
#    "com.adobe.pdf",
#    "Apple PDF pasteboard type",
#    "com.apple.pict",
#    "Apple PICT pasteboard type",
#    "dyn.ah62d4rv4gk8y4zcrna",
#    "CorePasteboardFlavorType 0x4D544D50"
#)
#
from AppKit import NSPasteboard
pb = NSPasteboard.generalPasteboard()
print pb.types()