Depth of Field <> Field of View

Below are two photographs, taken one right after the other, using the EOS 30D and EOS 5D with a Sigma 105mm Macro lens, pointing at a yardstick from the same exact distance using a tripod. I'm manually focusing on the 20 inch mark of the yardstick. The only obvious difference between the shots is the field of view (not to be confused with the depth of field.) The EOS 5D will give a wider field of view than the 30D using the same focal length lens. If you examine the depth of field provided in both shots by tracing the yardstick from the 20 inch mark, you'll see that the focus field is roughly identical.

EOS 30D, Sigma 105mm Macro/f2.8/ISO 100 EOS 5D, Sigma 105mm Macro/f2.8/ISO 100

I can't think of any better way to explain this than by using actual photographs. The depth of field is the same, the field of view is different. The crop body does not modify the depth of field.