The mtd partitions are a bit strange for the LG. Most of those tools mount to different partitions.
You may try emergency restore by pressing VOLUP+VOLDOWN and keep the power-button pressed when power up.
If USB is pluged you will enter emergency mode. This should do the trick.
btw. I am still looking for downgrade to 2.2 :-(
This damn 2.2.1 locked me out! Now google and LG are root on MY device! This sucks.