Last year (see http://dev.eclipse.org/mhonarc/lists/m2e-users/msg03633.html
) I reported an m2e issue I was having with the maven-jar-plugin, the short story being the error:
The suggested workaround (downgrading the maven-jar-plugin from 2.4 to 2.3.2) made the problem go away. All that happened in the context of Indigo and m2e 1.2. Recently I've been trying to update by dev environment to Kepler and m2e 1.4 and the problem returned, even though I'm still using the workaround. Removing the workaround didn't fix the problem either.