You can take your meter to a good camera repair store for calibration then try again.
As a side note I just attended a Will Crocket seminar which dealt with exposure and color spaces. The first half of seminar is on lights setup and meter readings. He feels that digital only has a range 6.5 stops unlike film with it's 10 stop range. This means that exposures can only be .05 under or .03 over and meters are needed for spot on exposures rather than depending on the camera or even the in camera histogram.
Here is his system for digital exposure. Dome on the meter, Aim at light sources first for lighting ratio, then under the chin and aimed at the lens for the camera setting. Custom white balance and you are ready to go.
For more information you can check his web site at http://www.shootsmarter.com/