C. - Congrats on the new baby. I know that pumping for a preemie is a lot of work. I have several mommies who are in the same boat you are. Most likely what is happeneing is the white valves are not pressed into the yellow valve tightly. Make sure each time you clean your parts you need to remove the yellow valve from the flange and take the white membrane off. Clean that valve inside and out really well. If the surface of the yellow valve is damaged, cracked or dirty the white valve may not seal really well thus you will get seriously decreased or non existant suction. You might want to get an extra set to have around just in case you need them. You can not afford to skip pumping for your baby. You need to be pumping about 8 times in 24 hours at least 15-20 minutes each time. At night you need to pump at least once. If the Lactina doesn't work well enough for you, you might want to try the Symphony.
Good Luck & Happy Pumping,
J. Bailey, CD, CBC at www. everymotherandchild.com