  The magnetization around the superconducting transition was measured in a
Tl$_{0.5}$Pb$_{0.5}$Sr$_2$CaCu$_2$O$_7$ crystal affected by a considerable
reduction ($\sim$55%) of its effective superconducting volume fraction but
still with a relatively sharp low-field Meissner transition, a behaviour that
may be attributed to the presence of structural inhomogeneities. By taking into
account these inhomogeneities just through the Meissner fraction, the observed
diamagnetism may still be explained, consistently above and below the
superconducting transition, in terms of the conventional Ginzburg-Landau
approach with fluctuations of Cooper pairs and vortices.
