Below is a copy of email sent to your email address (alrewards.com) on Apr. 07, 2011
I had no problems to convert an HTML with your image to PDF (see attached).
Is it exactly the same image, that caused the problem? As I see in your HTML sample there is no test_png.png reference.
Also in the servlet code please try to invoke
method before pd4ml.render()
Does it change anything?