Original: M. L. West writes that the story of Pandora and her jar is from a pre-Hesiodic myth, and that this explains the confusion and problems with Hesiod's version and its inconclusiveness.
Simplified: According to M. L. West, the story of Pandora and the jar is older than Hesiod's versions. This also explains the confusion and problems of Hesiod's version and that it is inconclusive.