Ok, here's what I'm doing. I'm making a gun and was going to use the "boolean" procces to put holes in the barrel part. (air holes to keep it cool) I created a cylinder, positioned it straight up and down and in the middle of the barrel so that both the north end and south ends stuck out a little past the surface of the barrel. Since the cylinder dissapears every time you do booleans, I decided to duplicate the cylinder and position all the duplicates in their respective places beforehand. Now, I select the barrel of the gun, select one of the cylinders, choose Polygons>Booleans>Difference. It works. I have two nice air holes in my barrel. I repeat the same thing with about 8 of the other cylinders, but on the ninth one something goes wrong. I select the barrel, select the cylinder, Choose Polygons>Booleans>Difference, and the BARREL dissapears. I am left with all the other cylinders staring me in the face. The output window pops up and says "Problem in Resolve NonSolidShell." I cannot get any farther with the creation of the barrel. Help.