The other culprit could've been an adhesive the company used to tack the material down with. It's a spray adhesive (sort of like contact cement) that's used to hold prepreg in a particular place while other parts are pressed into the geometry of the mold. The adhesive keeps critical areas from shifting. In our case this was used to keep the material down in the trough of the corrugation mold while the webs and top surfaces were being shaped. In our case we think this too is a likely culprit because if the volatiles are not dissipated when the fabric is laid down, they could dilute or even dissolve the resin in the first couple of layers. Normally the procedures for this type of layup are set so that this doesn't happen but it is still a possibility.