drawing models

[Aranda]

Sounds like your depth buffer states are not being set correctly. Tom explains how to do it in this thread:

"z buffer"(depth buffer?) does not appear to work as described in an XNA tutorial

That isn’t the correct way to do that and will get you into trouble. Instead just do this: GraphicsDevice.DepthStencilState = DepthStencilState.Default; That is the correct way to do what you want.