PNG Graphics won't display in LaTeX

I have trouble with graphics in LaTeX. I am using Kil under ubuntu.

I first tried including .png images, then got the classic no 开发者_开发百科bounding box error. When I switched to .eps, I got no errors but no images in the input!

Included graphics package:

 \usepackage{graphicx} 

And used a simple:

\includegraphics{figures/arch2.eps}

you must include the package \usepackage{epstopdf}

This error is normal if you use latex for conversion, so I'm almost sure you're not using pdftex for conversion, as you should if you want to insert figures other than eps.