Enhanced Busybox fixed the -ih issue. Output:-

BusyBox v1.23.1 (Debian 1.23.1power2) built-in shell (ash)
Enter 'help' for a list of built-in commands.

gainroot
Root shell enabled


BusyBox v1.23.1 (Debian 1.23.1power2) built-in shell (ash)
Enter 'help' for a list of built-in commands.

Nokia-N900:~# df -ih
Filesystem Inodes Used Available Use% Mounted on
rootfs 0 0 0 0% /
ubi0:rootfs 0 0 0 0% /
tmpfs 28.7K 52 28.7K 0% /tmp
tmpfs 28.7K 35 28.7K 0% /var/run
none 28.7K 721 28.0K 2% /dev
tmpfs 28.7K 3 28.7K 0% /dev/shm
/dev/mmcblk0p2 128.0K 13.3K 114.7K 10% /home
/home/opt 128.0K 13.3K 114.7K 10% /opt
/opt/pymaemo/usr/lib/python2.5
128.0K 13.3K 114.7K 10% /usr/lib/python2.5
/opt/pymaemo/usr/share/pyshared
128.0K 13.3K 114.7K 10% /usr/share/pyshared
/opt/pymaemo/usr/lib/pyshared
128.0K 13.3K 114.7K 10% /usr/lib/pyshared
/opt/pymaemo/usr/share/python-support
128.0K 13.3K 114.7K 10% /usr/share/python-support
/opt/pymaemo/usr/lib/python-support
128.0K 13.3K 114.7K 10% /usr/lib/python-support
/dev/mmcblk0p1 0 0 0 0% /home/user/MyDocs
/dev/mmcblk1p1 0 0 0 0% /media/mmc1
Nokia-N900:~#