I have a small JSF web app. When performing exploded deployment, after a ".dodeploy"/."undeploy"/".dodeploy"/".undeploy" cycle, the manifest.mf files are locked (I cannot delete the files, Windows tells me that they are used by a Java process)
A similar sample without JSF (and beans.xml) does not show this problem.
See the forum post for more details and the zip file of the "to be deployed" app.