mountd doean`t start when ZFS is enabled.

[Михаил Кипа]

I have two servers with Identical FreeBSD7.2 system. On both I have such config in /etc/rc.conf:
rpcbind_enable="YES"
rpc_lockd_enable="YES"
rpc_statd_enable="YES"
nfs_client_enable="YES"
nfs_server_enable="YES"
nfs_server_flags="-u -t -n 5 -h 192.168.x.y"
mountd_flags="-r"
where "x" identical for both servers and "y" is differs by one. On one server I have ZFS storage, so 
that in rc.conf I have:
zfs_enable="YES"
On server where no ZFS storage NFS server works well and mountd starts at server startup 
automatically. But on the server with ZFS storage mountd couldn`t start on startup with such error:
mountd[855]: bindresvport_sa: Address already in use
when I correct rc.conf to:
mountd_flags="-r -p 998"
mountd begins to work.
So, is it corrct behaviour of mountd with zfs? On 7.1 anything works well, but after cvsup and 
recompilation system has falled in such troube. May be it is a bug?