Sometimes it is useful to reset slopes and albedos, such as when there is an artifact (such as from an improperly aligned image) that is giving trouble. Doing this too often (such as while iterating) will degrade the shape since you keep throwing away useful information.
You can reset either slope or albedo, or both.
Main Menu: Q 0123O IUCRSG NVAMBX DEPL FZH? a >a Reset slopes? (y/n) y Reset albedos? (y/n) y