P2414H Difficulties Cleaning / Weird Anti-glare Coating?

Received a new P2414H today and after unpacking (the seal was intact) I noticed some big fat fingerprints on the screen.

Tried to clean them the usual way, with a damp microfibre cloth, but can't achieve a clean, uniformly matte black surface. It seems as if I would smear around some slight fatty dirt with the cloth.

Also tried with a 50/50 mixture of water and isopropyl alcohol as per http://www.dell.com/support/article/us/en/19/SLN153766/EN 

I have never experienced anything similar with my U2312, or any other monitor for that matter.

I even thought about returning it, but the picture quality is first class and I seriously doubt the replacement would have a different coating :))

I will hugely appreciate any ideas or suggestions!

Andrej