7.2b3 postmaster doesn't start on Win98

When trying to start the postmaster on win98se with cygwin
I get told that the data directory must be 0700, but when I try to chmod to
700, it apparently succeds, but nothing permissions stay at 755. I suspect
this to be because win98 has no real file protection (just a read only
attribute)
(uname -a:
CYGWIN_98-4.10 BX3551 1.3.5(0.47/3/2) 2001-11-13 23:16 i686 unknown)
- Stuart