Rich:
I did a lot of transfer molding of microelectronic packages during my engineering career. This stuff is probably injection molded but the concept should be the same. For warp as bad as what some are saying above it sounds like the parts were separated from the mold while they were still too hot (ie soft) and/or allowed to cool too rapidly. I never encountered a 1 inch warp. All warp pieces I have worked with always were straightened out with clamps and glue.
Dan:
From your email it sounds like you taped the walls together and noticed the warp. I have had this issue too but if I clamp (takes the warp out) and glue the walls together and let them sit over night the glue keeps them straight. I use Plastruct Plastic Weld.
As Melgar stated using a 1/4 inch thick square wood rod and clamping overnight should take out the warp. Don't use plastic rods. My experience has been when taken out of the clamp the rod conforms to the bend in the wall.
