<EDIT>I just saw that you included this in your post....I glazed over it thinking it was a signature</EDIT>
In your project directory should be a .map file. If you open it with a text editor you can find out how much memory you're actually using. Look for the section that looks like this
Code:
Program Memory Usage
Start End
--------- ---------
0x000800 0x0050a7
18600 out of 132120 program addresses used, program memory utilization is 14%