Illustrator EPS coming up low res in Acrobat preflight

[Amybeth M. ACI G7]

I am working on a huge sticker book where all the images are placed as EPS files.
At this point resaving them as AI files causes them to not update properly.

When I run the acrobat prefilight it shows that even though all the images are100% vector, are "low res"

The are scaled at all different percents.

I am also working on resolving ink density issues which is another task! 

Any feed back would be appreciated