  Although calculations of the $b\rightarrow s\gamma$ rate in supersymmetric
grand unified models have always either ignored the gluino mediated
contribution or found it to be negligible, we show that taking universal
supersymmetry breaking masses at the Planck scale, rather than at the gauge
unification scale as is customary, leads to the gluino contribution being more
significant and in fact sometimes even larger than the chargino mediated
contributions when $\mu >0$ and $\tan{\beta}$ is of order 1. The impact is
greatest felt when the gluinos are relatively light. Taking the universal
boundary condition at the Planck scale also has an effect on the chargino
contribution by increasing the effect of the wino and higgsino-wino mediated
decays. The neutralino mediated contribution is found to be enhanced, but
nevertheless it remains relatively insignificant.
