I just tried mounting a Linux export from an old FreeBSD box. It worked.
1. What is your mount command?
2. What does your exports file look like?
I did not have any problems with exports as:
/home/pictures 192.168.0.0/255.255.255.0(rw,no_root_squash)
and this mount command (from freebsd):
mount dual:/home/pictures /mnt