The Collaborative International Dictionary of English v.0.48:

Ineffectiveness \In`ef*fect"ive*ness\, n.
   Quality of being ineffective.
   [1913 Webster]

WordNet (r) 3.0 (2006):

ineffectiveness
    n 1: lacking the power to be effective [syn: ineffectiveness,
         ineffectualness, ineffectuality] [ant: effectiveness,
         effectivity, effectuality, effectualness]