This has been seen in the last two EMBJOPR-JSFUNIT test runs (#316 and #317) on Hudson.
http://hudson.qa.jboss.com/hudson/view/JBoss AS/job/JBoss-AS-5.1.x-EMBJOPR-JSFUNIT

java.lang.OutOfMemoryError: Java heap space
[09:20:39.845][info][talledLocalContainer] at java.util.zip.ZipEntry.initFields(Native Method)
[09:20:39.845][info][talledLocalContainer] at java.util.zip.ZipEntry.<init>(ZipEntry.java:100)
[09:20:39.846][info][talledLocalContainer] at java.util.zip.ZipFile$3.nextElement(ZipFile.java:437)
[09:20:39.846][info][talledLocalContainer] at java.util.zip.ZipFile$3.nextElement(ZipFile.java:415)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.plugins.context.zip.ZipEntryContext.initEntries(ZipEntryContext.java:481)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.plugins.context.zip.ZipEntryContext.ensureEntries(ZipEntryContext.java:609)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.plugins.context.zip.ZipEntryContext.checkIfModified(ZipEntryContext.java:763)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.plugins.context.zip.ZipEntryContext.getChildren(ZipEntryContext.java:835)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.plugins.context.zip.ZipEntryHandler.getChildren(ZipEntryHandler.java:159)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.plugins.context.DelegatingHandler.getChildren(DelegatingHandler.java:121)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.plugins.context.AbstractVFSContext.getChildren(AbstractVFSContext.java:215)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.plugins.context.AbstractVFSContext.visit(AbstractVFSContext.java:332)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.plugins.context.AbstractVFSContext.visit(AbstractVFSContext.java:372)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.plugins.context.AbstractVFSContext.visit(AbstractVFSContext.java:302)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.plugins.context.AbstractVFSContext.visit(AbstractVFSContext.java:370)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.plugins.context.AbstractVFSContext.visit(AbstractVFSContext.java:372)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.plugins.context.AbstractVFSContext.visit(AbstractVFSContext.java:372)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.plugins.context.AbstractVFSContext.visit(AbstractVFSContext.java:302)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.VFS.visit(VFS.java:433)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.VirtualFile.visit(VirtualFile.java:437)
[09:20:39.846][info][talledLocalContainer] at org.jboss.virtual.VirtualFile.getChildrenRecursively(VirtualFile.java:422)
[09:20:39.846][info][talledLocalContainer] at org.jboss.seam.integration.jbossas.vfs.VFSScanner.handleRoot(VFSScanner.java:169)
[09:20:39.847][info][talledLocalContainer] at org.jboss.seam.integration.jbossas.vfs.VFSScanner.scanDirectories(VFSScanner.java:117)
[09:20:39.847][info][talledLocalContainer] at org.jboss.seam.deployment.WarRootDeploymentStrategy.scan(WarRootDeploymentStrategy.java:72)
[09:20:39.847][info][talledLocalContainer] at org.jboss.seam.init.Initialization.redeploy(Initialization.java:777)