Grain/Noise problems

I have submitted about 10 or 12 photos. Most rejected for grain or noise. A couple I understand. The rest I don't understand. I can't see the grain or noise problem. Is anyone else having this problem? Has anyone figured out how to avoid the problem? I use ACR and Photoshop for post-processing. I would love to post more photos but it is getting very frustrating when 90% are rejected. I've had photos published in a book and various magazines. Not sure what I can do to get around this objection.

I'm not near my office so I can't upload a pic right now.