Andrew Gillis , Apr 22, 2009; 02:31 p.m.
If the meter is consistently underexposing, you can try two things: first, and easiest, set a lower ASA/ISO speed than the film speed or ISO on your digital camera on the meter. Change it until you get results that you like. You can also look for an adjustment screw on the back of the meter--most handheld meters have one, and then use a jewelers screwdriver to adjust it until you get accurate readings.
As for taking flash readings, put the meter in the same place as your subject and point the white dome back toward the camera and take a reading. Good luck.