Well, I already found the exception and fixed it, but not thanks to the trace, I remember that once I got a problem similar and Egon provide of a version of jpct in which all this thigs were fixed! so why dont to add that features to the official version.
BTW: Talking about the joct engine cidification, I want to suggest to avoid sendind console messages on certain situation but throw an exception, for example when retireving an object from the world, if the object is not found it returns null but also sends a console message, or when blitting an image that may go furteher than the screen. Sending console mesasges is not good for the estetic and for debugging! for example I use to sed console messages to find a error but if for each iteration I receive that jpst messages i cant even see my own text. When something os worng it may throw and exception to let the developers handle it and take action if it happens but if just sending a message programmers have no control over that situation.