If you enable the Java Console, and then start up the following JNLP, the console comes up and the warning comes up about the digital signature cannot be verified. Clicking Run closes the console and the warning, and then the console and the warning come up again. Clicking Run again then starts the program. If you reduce the max-heap-size to 256m or below, you only get asked once. Is there a way to use a max-heap-size of greater than 256m and have the console and the warning come up once only?