More details please?
What version of the DW20 pack?
What material are you trying to pour?
What are you trying to pour it on? (Wood hasn't worked as a model for some time now, use cobble)
Be warned that making a cast with default IguanaTweaks results in the loss of the original, so don't make a cast using anything valuable.
I don't know about Minechem or DimDoors, but I have IT installed but disabled on DW20 v1.1.1 for now... I'll check it later as a test and edit this post.