chroot permission denied --loged in as root!! howcome?

linux-u8mt:~ # chroot /mnt/hda10 /bin/bash
bash: /dev/null: Permission denied
linux-u8mt / #

/mnt/hda10 is gentoo install with 2.6.27 kernel
i dont see any reason for denying permission to chroot

anybody can tell me why?

How is that partiton mounted? Is nodev in the list of options enabled, either explicitly or implicitly? That would prevent /dev/null on that partition to be correctly handled.