There was a variation for the Vintage Collection Stormtrooper VC41 figure. The first released Stormtrooper didn't have the abdominal buttons painted. Have a look at the comparison pictures below, the first release is on the left, the corrected version is on the right.
VC41 Stormtrooper variation, pictured on the left is the first version with unpainted abdominal buttons, on the right the corrected release.