Bill,
Your image looks fine on my screen.
Regarding monitor calibration, I take a slightly different approach. I calibrate my
printer, using Monaco EZcolor software, their reference print, and a scanner. Then I adjust my monitor so that what I see on it matches what the printer cranks out. That automatically compensates for the effects of room lighting. It also accomplishes what I care most about, which is using my printer as a local proofing device for files to be printed remotely by a high end graphic arts company (
http://www.calypsoinc.com/).
The last time I checked, monitor calibration is still a cross between a black art and an exercise in frustration and futility. PC and Macintosh monitors are generally set for different gammas, and color management software still hasn't penetrated all the browsers that are in common use. That's the bad news. The good news is that most people are not very sensitive to either color casts or brightness, until they start trying to match colors on a side-by-side basis. If you're trying to make images that will look good to people all across the web, you have to compromise anyway.
This article is somewhat dated, but it's a good overview of the issues.
The other thing to do is visit
dpreview and make sure you can see all the blocks on their gray scale (scroll to bottom of page). This should be OK with a new LCD monitor, but it's always worth checking. With my monitor (matched to my calibrated printer), the darkest Y and Z blocks can be distinguished only by careful study, preferably in a darkened room. Under normal room lighting, X, Y, and Z are all black at first glance, and a Kodak neutral gray card matches brightness someplace between blocks P and Q.
--Rik