haha, was missing /system/xbin from the path
sorted that out, ran the cat /sdcard/boot.img > /dev/block/nandc
AND IT'S UNBRICKED
thank god i had a copy of the original boot.img

Cheers for your help bud, but i suspect to get it working these are the steps you'd need to take...
1) in linux (because it handles permissions the same way) grab a copy of another android's /system/bin /system/sbin and /system/xbin folders & contents
2) chmod all these files to 755
3) boot bricked extreme into recovery
4) push the above files onto extreme
5) push boot.img onto extreme (/sdcard/boot.img)
5) adb shell
6) PATH=$PATH:/system/xbin
7) this:
suggsy89 wrote:No you wont be able to dd it back, you will have to cat it back...
Code: Select allcat /sdcard/boot.img > /dev/block/nandc
sync
sync
reboot
That should do the trick, if not youve also borked your system partition
Anyway, i'm now back to the original problem where the /data /cache haven't been mounted and /system is always mounted as rw
I am 100% convinced that a copy of a working extreme's /system should sort that out, as i imagine the problem struck when i tried installing busybox off the market (which must have deleted/overwritten something)