[clkeiper]

I really think a lot of "helmet head" is caused by lack of humidity as the seed starts to emerge. even if the media is damp the humidity can be low and the seedshell dries out faster than it can be shed off the cotyledons. When this happens to me I pour just a tiny bit of perlite (not vermiculite) on the affected ones and make sure I keep the container covered lightly... maybe an open clamshell top or un-fastened plastic wrap... whatever so it doesn't get too hot or stay too wet and cause a fungal issue.