phonegap push plugin class not found

phonegap push plugin class not found

I'm trying to add a push plugin on my android version of phonegap.
(https://github.com/phonegap-build/PushPlugin)
But I have a problem when I launch I have an error:
08-23 11:35:12.849: W/System.err(22031): Caused by:
java.lang.ClassNotFoundException: com.plugin.GCM.PushPlugin
I think the config.xml is trying to load the PushPlugin:
<plugin name="PushPlugin" value="com.plugin.gcm.PushPlugin" />
But I don't understand because my file exist.
com
plugin
gcm
PushPlugin.java
In the error gcm is on upper case this is maybe the error but I don't know
how to correct it