Digital BW, The Print

When using the "print to file" feature Qimage changes a grayscale to
RGB. Has anybody noticed a difference when printing the 16 bit RGB
file through QTR vs. printing a grayscale? I printed one in RGB and
one in grayscale (changing it back in Photoshop) and the RGB seems
noisier than the grayscale.

Did I miss the reason given in the Qimage group for why Qimage won't
print grayscale or why that feature can't be incorporated?

Thanks,

Tom