ClassNotFoundException on app startup (on device)

I have been able to run my app exactly ONCE on the device (N8). Since then I always get a ClassNotFoundException when I launch it. It goes like this:

ClassNotFoundException: com.greencod.pinball.nokia.PinballMIDLet at java.lang.Class.forName at ...rtCldc.loadApplicationClass at ...rt.jvm.loadApplicationClass at ... Invoker.handleStarRequest at ...l.rt.midp.MidleInv开发者_Go百科oker.run at java.lang.Thread.run

Note that the app runs fine on the emulator. Also, the first time that it ran was througth the debugger in eclipse. Now the debugger or a plain install doesn't produce an app that can run. I am new to Nokia development, so I must be doing something stupid, I just don't know what :) I am using the Symbian^3 SDK 0.9.

To get the application on the phone, I click 'create package' from the manifest view, which build the jar/jad files for 2 targets: SymbianEmulator and SymbianDevice, which I installed by scanning the SDK folder. After I have tried uploading the file to the device by dropping it in the Install folder, by using the debuger in eclipse and with the Ovi program on my computer. The phone itself is configured to accept unsigned application.

I am quite lost and any help is welcome.

Additional Info

Eclipse is building the jad for me, so I'm not sure that is the problem. Here is the jad file:

MIDlet-1: Pinball Deluxe,,com.greencod.pinball.nokia.PinballMIDLet
MIDlet-Jar-Size: 1882
MIDlet-Jar-URL: Pinball-MIDLet.jar
MIDlet-Name: Pinball Deluxe MIDLet
MIDlet-Vendor: GreenCod
MIDlet-Version: 0.1.0
MicroEdition-Configuration: CLDC-1.1
MicroEdition-Profile: MIDP-2.1
Navi-Key-Hidden: true
Nokia-MIDlet-App-Orientation: portrait
Nokia-MIDlet-On-Screen-Keypad: no

And here is my class declaration:

package com.greencod.pinball.nokia;
import javax.microedition.lcdui.Display;
import javax.microedition.midlet.MIDlet;

public class PinballMIDLet extends MIDlet { ... }

It has been solved: nokia forums. Basically the problem was that the build.properties of the project were messed up.