I too have been struggling with the best way to calibrate this Dell 2407 monitor. I have the eye-one Display 2 device and using Eye-One Match 3 v3.6.2, I am also running Windows Vista Ultimate and have the ATI Radeon 1650 Pro.
I am able to calibrate this thing down to 80 Luminance using just the brightness on the monitor. I never touch the graphic drivers and I leave the monitor RGB at 100.
I went back and forth with Gretag support and got someone who really knew the product and how to calibrate. I was told that to get the best calibration, it was better to not use the RGB on the monitor, and just leave the monitor at defaults. Apparently the RGB controls on these cheap monitors are not real RGB controls and tend to cause more issues. I was told to stick to adjusting brightness only on the monitor since I use DVI (there are no contrast controls for DVI).
Oddly, my same monitor and video card calibrated great under Windows XP using 6500k 2.2 120 lum. But on Vista 120 lum still washes out my blacks, they look like glowing greys. So I kept choosing a lower and lower lum and eventually the 80 lum and 90 lum looked like real inky black. Not sure if this is a bad thing or not, but I am currently at 6500 2.2 and 90lum with only touching the monitor brightness down to 32.
I also tried calibrating using the laptop choice in the Match software but all this seems to do is skip the RGB controls and contrast which is something I do anyways when using the LCD choice. I started skipping the RGB after speaking to the Gretag tech.
Also, another hidden gem for those of you using the Match software. After you calibrate just click next to get back to the front screen of the Match software. There is a nice tool I never new about that you can use to validate your profile. It is greyed out when you first launch the match software, but right after a calibration if you click next you can run this, it will then test your calibration. I was told anything under 1.0 is a good result. I tend to always end up at .42 to .44
Here is the quote from the Gretag tech that explains this better.
Make a profile at 6500k, and Gamma 2.2, then at the end Do Not Click Finish but click the right arrow again. this will take you back to the start of that application, then go up to the menu bar and look for Start Monitor Validator. This will run a program that will allow you to see how well your monitor works with a profile at those settings. this is a really neat program in that it will give you values in Delta E which is how color differences are measured, the lower the better. Most Apple Cinema Display's have a Delta E of less than 1, but I have a really cheap 17" Acer at home that has a Delta E of around 2 and my monitor cost all of $140 brand new. Delta E of 1 is the minimum change in color someone with Highly Acute color vision can see. The average person can not see a change until
around Delta E of 2-3. Another way to imagine this Delta E value is if you held two prints that had a Delta E value difference of 5, you could see the difference when held next to each other, but by the time you moved them 2 feet apart, you could no longer see a difference, that's how small 1 Delta E is.
You can play around with settings when you profile your monitor and see what makes your overall Delta E higher or lower, sometime native will actually be worse and have a higher delta e then using 6500k and Gamma 2.2. The monitor I'm using here, has a lower over all Delta E when I use 6000k for instance, there really is no way to guess at what will work best on your monitor but I'd still say 6500k and Gamma 2.2 is your best bet.
In any case I guess I am sticking with 6500 2.2 and either 80 or 90 lum.