I do illustrations and I submit both vector and raster versions at the same time. Recently I've had some vectors rejected but the rasters approved and these rasters have sold (rasters do not sell as well as vectors normally). What I do in cases like this is resubmit the vector with a note to the reviewer and invariably they then approve the vector.

My thoughts here is this: how is it that one reviewer will reject an image yet another reviewer approve the exact same image albeit in a different format.

Yesterday it happened again, the raster approved but the vector rejected, resubmitted and waiting to see if vector gets approved today.

One illustrator contacted support a while ago on this same subject and the reply was that if one version was accepted then there is no reason why the other version of the same image should not be accepted (unless there is some technical error with the file), alas this scenario happens often these days.