As far as I understand the code, missing data here (and the `null` returned in that case) will translate in the StandardDrive (the Image) not being returned. So I see it as "if some image is missing a field jclouds needs, we're not returning them and can't be used in the portable abstraction".

This is how it was working before the change. But it's worth an issue if we feel this is not the right behavior.