  We analyze topological charge contributions from classical SU(2) center
vortices with shapes of planes and spheres using different topological charge
definitions, namely the center vortex picture of topological charge, a discrete
version of F\~{F} in the plaquette and hypercube definitions and the lattice
index theorem. For the latter the zeromodes of the Dirac operator in the
fundamental and adjoint representations using both the overlap and asqtad
staggered fermion formulations are investigated. We find several problems for
the individual definitions and discuss the discrepancies between the different
topological charge definitions. Our results show that the interpretation of
topological charge in the background of center vortices is rather subtle.
