Okay, so I made a 12-side cylinder, hollowed it out, did a few things to it, like carve out a window, and it's acting funny. As you can see from the pictures below, from the inside, you can see out through it in a certain spot, but look at it from the outside, and it looks perfectly fine. It's completely solid, it's just that you can see through it from the inside. What causes this? What can I do to fix it?
Inside the cylinder - http://casius4.netfirms.com/inside.jpg
Outside the cylinder - http://casius4.netfirms.com/outside.jpg
Thanks