KAIO problem with Online 7.12 on AIX 4.1.4

I am currently using Online 7.12.UC1 on an AIX 4.1.4 platform. Because my dbspaces are created with raw device chunks, the I/O's should be performed by the KAIO threads. Thus, the I/O's should be performed by the CPU VP. However, when I issue the onstat -g glo command, I notice that the AIO, PIO and LIO VPs are spending user/system time. Moreover, when I issue the onstat -g iob command, the KAIO row only contains 0 whereas the aio one does not. As a consequence, I suppose the KAIO's do not work on my platform. Is someone has experimented such a problem ? Is there a way to make the KAIO's work on AIX 4.1.4 ?