Switched back to ironjacamar 1.0.12.Final in pom.xml and made a new build of JBoss AS7.
Tata: problem disappeared.
sb2000.[maj2e_langfr]/mbi/mbi2e_all. egrep -i "(DEBUG|filesys)" `jbosslogfile` | pg
09:03:45,471 INFO [org.jboss.as.server.deployment#start] JBAS015876: Starting deployment of "filesystem.rar"
09:03:45,599 INFO [org.jboss.as.server.deployment.scanner#startScanner] JBAS015012: Started FileSystemDeploymentService for directory /mbi/tools/jboss/7.2/standalone/deployments
09:03:51,846 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemResourceAdapter#setPath] /mbi
09:03:51,848 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemResourceAdapter#setPath]
09:03:52,052 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemResourceAdapter#setPath] /mbi
09:03:52,071 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemResourceAdapter#setPath]
09:03:52,074 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemManagedConnectionFactory#<init>]
09:03:52,075 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemManagedConnectionFactory#<init>]
09:03:52,076 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemManagedConnectionFactory#setLogWriter] java.io.PrintWriter@de1cb6
09:03:52,077 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemManagedConnectionFactory#setLogWriter]
09:03:52,078 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemResourceAdapter#hashCode]
09:03:52,079 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemResourceAdapter#hashCode]
09:03:52,079 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemManagedConnectionFactory#setResourceAdapter] biz.mbisoftware.fn.jca.filesystem.FilesystemResourceAdapter@a11663
09:03:52,080 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemManagedConnectionFactory#setResourceAdapter]
09:03:52,119 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemManagedConnectionFactory#createConnectionFactory]
09:03:52,120 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemManagedConnectionFactory#createConnectionFactory] biz.mbisoftware.fn.jca.filesystem.FilesystemConnectionFactoryImpl@161c602
09:03:52,121 INFO [org.jboss.as.connector.deployment#bindConnectionFactory] JBAS010406: Registered connection factory java:/Filesystem
09:03:52,129 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemResourceAdapter#start]
09:03:52,130 DEBUG [biz.mbisoftware.fn.jca.filesystem.FilesystemResourceAdapter#start]
09:03:52,303 INFO [org.jboss.as.connector.deployers.RaXmlDeployer#createObjectsAndInjectValue] IJ020002: Deployed: file:/mbi/tools/jboss/7.2/standalone/tmp/vfs/temp533fa173e0480750/filesystem.rar-e40ac13931b7ec47/contents/
09:03:52,367 INFO [org.jboss.as.connector.deployment#transition] JBAS010401: Bound JCA ConnectionFactory [java:/Filesystem]
09:05:13,004 INFO [org.jboss.as.server#handleResult] JBAS018559: Deployed "filesystem.rar"
Seems something has been broken from 1.0.12 to 1.0.13.