Root fails after update. HELP!

[fiddlincujo]

i recently just installed the update 98.12.4.XT907.Verizon.en.US system version. Had root access before the update. Now i still have the superuser app, but root doesn't work. Tried to find a way to unroot, no luck. tried to install root again, no luck. Can someone tell me how to get the root back or get back to the system version where the root did work??? running android version 4.1.1

Droid RAZR M