After step 3 my n900 does this :

Nokia-N900:~/n900_720p# ./mount_n950_rootfs.sh
umount: cannot umount /tmp/n950loop: Invalid argument
losetup: /tmp/n950loop: No such device or address
Reading package lists... Done
Building dependency tree
Reading state information... Done
wget is already the newest version.
liblzo2-2 is already the newest version.
p7zip-full is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 45 not upgraded.
/usr/bin/7z: exec: line 2: /usr/lib/p7zip/7z: Too many levels of symbolic links
7z archiver not found.
On n900 it is a part of p7zip-full package
You may try to install it with "sudo apt-get install p7zip-full"
Nokia-N900:~/n900_720p#

After i rebooted i was unable to watch any movie in osso-mediaplayer.

Any help?
Thanks for the awesome job freemangordon