Upload fails immediately on first product with image not found. It is a full HTTP address to an active site, and I can copy the address directly from the error message to firefox address bar and the image pops right up.

Had to kill the image addresses from my conversion script to even get it to import.

Error message:

Column 1, error in value "http://www.myracytoybox.com/shopsite_sc/store/html/media/prods/AL1007XO.jpg".
Reason: Image "http://www.myracytoybox.com/shopsite_sc/store/html/media/prods/AL1007XO.jpg" does not exist.

Sounds like a permissions issue, Make sure you have permissions to read and write to that location.