jmoore

sounds like 'damping off' it's a fungal disease that loves damp conditions. You need to get as much air to them as possible, don't over water and if you can spray the seedlings with a weak (I mean weak, half a teaspoon to 1 litre of water) copper based fungicide, there is something called cheshunt compound, which is available over here, not sure about its availabilty over in the states. I noticed my velutina being particularly vulnerable to this problem.