It most likely has nothing to do with 64bit and more to do with UAC being enabled. See the following threads for more info. Post back with further questions.

http://www.kixtart.org/forums/ubbthreads.php?ubb=showflat&Main=26830&Number=198514
http://www.kixtart.org/forums/ubbthreads.php?ubb=showflat&Number=199692#Post199692

By the way, the kix.dlls are not needed unless you are supporting win9x clients.