In reply to oldrichie:
Sounds like you are doing all you can camera end (bar auto ISO).
It's now down to your Post Processing.
If you've got access to the latest Camera RAW processing plugin in Photoshop, then it will be the same noise reduction approach as in Lightroom. [buy Lightroom anyway its much easier overall compared with Photoshop]
There are tricks (more of an art/taste than strict approach) in Lightroom - its a combination of general processing tools, sharpening tools (with masking) and noise reduction tools, you can also add Grain back in. Often good to go to B&W sometimes.