06/19/2006(slc) - this bug exists on both the non-IBM
and IBM side of things. Since 'BPatch_address' is
defined to be 'void *', on a 32-bit platform the
resulting 64-bit AisAddress values will be sign-
extended rather than zero-extended when a simple
single cast (as done in the original code) is done.
(From Todd Smith, SGI)