Hi there! I actually just went through something similar for the last 5 hours! grrrr!BUT I finally found the solution...
With Norton (NAV) running the autoprotect, go into the options menu>NAV options
Click on "autoprotect" in left column
Click on "advanced" tab
Check the "load autoprotect at system boot" check box
Make sure your autoprotect settings are set to "try to repair then quarantine if unsuccessful"
Once your started up, go back into NAV and click the reports tab>
view quarantined items
Here you'll see the file__.dll (mine was wav.dll)
Now you can delete it! finally!!!
be sure to use hijackthis to remove the processes from startup. (it will indicate that the file was not found).
remove those and you're done!