It is pointing to the correct path.
emulator path:
D:\emulators\Naomi\demul0582\demul.exe
plugins path:
[plugins]
directory = D:\emulators\Naomi\demul0582\plugins\
I'm using Win7 SP1 64-bits. Maybe I'm missing a C++ Runtime library or something ? I have C++ 2005 / 2008 / 2010 / 2013 installed (both 32-bits and 64-bits versions).