I too had the same problem using TouchNooter to root my NST running BN's OS v1.1.2. I was able recover using this
TouchFormatter tool, but YMMV.
If you succeed, before attempting to root again, I would suggest that you update your NST to v1.1.2 (
not v1.2) and then back up your NST using
this procedure.
In case you want to make another run at rooting, IMHO the best rooting tool for v1.1.2 (again
not v1.2) is
MinimalTouch, its two-step process is a bit tedious but worked for me and many others.
Also you should take a look at
this thread for some more info on rooting the NST family.