Victor:

This appears to be a common issue when manufacturing. I would guess that they changed vendors, and this creates the variation. Each manufacturer processes art in a different manner (with different systems), as well as uses different presses, inks, materials, etc.

By your photo, I would say almost 100% that they simply changed suppliers. From your scan, the upper one appears to be of much better quality (from a printing standpoint). The manufacturer of the lower one didn't know what they were doing (black should never look gray).

Scott