Shadow Definition

I am printing with an Epson 3880, K7 warm neutral inks, and Canson Rag Photographique paper. I have been using a curve sent to me from your office on May 13 of this year (P2-WN-CANragPto curve). However, on some, but not all, prints there is a lack of shadow detail I think caused by a linearization problem, but I am not sure. I have agitated the ink cartridges and performed nozzle cleanings with no change. I have attached a scanned sample of the problem, Print Issue 7-26-13001.pdf, and am interested in having a custom curve made to address the problem if necessary.

I look forward to your comments.

Geoffrey Brune