AIX automount does not mount /net

I have a weird issue with AIX automounter ( At least in 5.1 and 5.2)

if I have a NFS server, name it "machine", that is exporting root
( / ) AIX automounter will not mount any mount point under /net/
machine.

If that NFS server stops exporting ( / ), then the AIX automounter can
access any of the exported file systems under /net/machine.

You might thing that I should not export / on my NFS server, but
unfortunately that is a must, I an talking about a NAS system.

You can do the test very easily. If the server you try to access with /
net/machine/share shows exporting ( / ) in showmounts -e machine, then
it would not work.

Any help would be appreciated