NoClassDefFoundError

Oi Pessoal, dentro da minha IDE (NETBEANS 7.0) o programa roda normalmente, quando compilo e tento executar o jar ele dá esse erro.
Alguem pode me dar uma judinha?

Abs!"

C:\Documents and Settings\leonardo\Meus documentos\NetBeansProjects\TCCLOCADORA\
dist>java -jar TCCLOCADORA.JAR
Carregando arquivos de propriedades
Carregando arquivos de propriedades
Tipo Banco de Dados : mysql
Vai Conectar ao banco
Exception in thread "AWT-EventQueue-0" java.lang.NoClassDefFoundError: br/com/lo
cadora/Cadastros/Cliente
        at br.com.locadora.dao.ClientesDao.listaClientes(ClientesDao.java:126)
        at br.com.locadora.gui.GUIClientes.listarClientes(GUIClientes.java:51)
        at br.com.locadora.gui.GUIClientes.<init>(GUIClientes.java:46)
        at br.com.locadora.gui.GUIPrincipal.mostraGUIClientes(GUIPrincipal.java:
125)
        at br.com.locadora.gui.GUIPrincipal.IMnuClientesActionPerformed(GUIPrinc
ipal.java:135)
        at br.com.locadora.gui.GUIPrincipal.access$100(GUIPrincipal.java:22)
        at br.com.locadora.gui.GUIPrincipal$2.actionPerformed(GUIPrincipal.java:
67)
        at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
        at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
        at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
        at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
        at javax.swing.AbstractButton.doClick(Unknown Source)
        at javax.swing.plaf.basic.BasicMenuItemUI.doClick(Unknown Source)
        at javax.swing.plaf.basic.BasicMenuItemUI$Handler.mouseReleased(Unknown
Source)
        at java.awt.Component.processMouseEvent(Unknown Source)
        at javax.swing.JComponent.processMouseEvent(Unknown Source)
        at java.awt.Component.processEvent(Unknown Source)
        at java.awt.Container.processEvent(Unknown Source)
        at java.awt.Component.dispatchEventImpl(Unknown Source)
        at java.awt.Container.dispatchEventImpl(Unknown Source)
        at java.awt.Component.dispatchEvent(Unknown Source)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
        at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
        at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
        at java.awt.Container.dispatchEventImpl(Unknown Source)
        at java.awt.Window.dispatchEventImpl(Unknown Source)
        at java.awt.Component.dispatchEvent(Unknown Source)
        at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
        at java.awt.EventQueue.access$000(Unknown Source)
        at java.awt.EventQueue$1.run(Unknown Source)
        at java.awt.EventQueue$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown
Source)
        at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown
Source)
        at java.awt.EventQueue$2.run(Unknown Source)
        at java.awt.EventQueue$2.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown
Source)
        at java.awt.EventQueue.dispatchEvent(Unknown Source)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
        at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
        at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
        at java.awt.EventDispatchThread.run(Unknown Source)
Caused by: java.lang.ClassNotFoundException: br.com.locadora.Cadastros.Cliente
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        ... 45 more

Obviamente, não está encontrando sua classe.
O que possivelmente está ocorrendo, é que você gerou o seu JAR sem que todas as classes estejam contidas nele.

Na realidade, você pode gerar N JAR´s, de acordo com sua necessidade.
A questão é que quando for executar o seu JAR, deve passar o contexto dele para o CLASSPATH, pois somente dessa forma ele vai encontrar as devidas classes.
Isso sua IDE faz automaticamente, algo que tu terá de fazer “na mão”, fora dela.

Abraços!