if i remember correctly this can happen when its run once with one set of adapters and then run again when adapter list or count changes.
try exiting url snooper, deleting the settings.ini or urlsnooper.ini file and then restart.
you do need to run url snooper in administrator mode by the way.
let me know if this works.
(ps. of course this shouldnt cause such an error, but i think this is what causes it)