Hmm, thats strange.
How could it look okay in histogram and the LCD and not look good on the monitor? :scratch:
Well, I had an issue last month when I was doing an engagement - low lit, no flash, ISO400, and on top of that I had intentionally underexposed some shots. I had to face the severe noise issue that you mentioned when I 'lifted' the image in RAW developer. I was forced to use Noise Ninja to clean 'em up.
Hope you are shooting RAW.