Debug in Eclipse - ClassNotFoundException

when i debug in Eclipse a simple console application, I get a lot of ClassNotFoundException lines in the debug Window. It is not an error, somewhat lower in another pane I get "Source not found.". I understand that it is because the source code of the required class is not available, buI would like to skip over these lines... I have to press a lot of times the "step over" or "step out" button to get out of these states.

What can I do in order to avoid these useless lines at all?

Thanks