For AS 5.2, if you have a WAR inside an EAR, the TLD scanning will throw an exception. You will get a ZipException on Linux or a FileNotFoundException on Windows:

13:11:12,953 ERROR [TldConfig] Exception processing JAR at resource path C:\projects\jboss5\Branch_5_x\build\output\jboss-5.
2.0.Beta1\server\default\tmp\abbt-9bqvlk-g08c290u-1-g08c3h2e-9t\servlet-1.0.war\WEB-INF\lib\commons-collections-2.0.jar in c
ontext /servlet
java.io.FileNotFoundException: C:\projects\jboss5\Branch_5_x\build\output\jboss-5.2.0.Beta1\server\default\tmp\abbt-9bqvlk-g
08c290u-1-g08c3h2e-9t\servlet-1.0.war\WEB-INF\lib\commons-collections-2.0.jar (Access is denied)
at java.util.zip.ZipFile.open(Native Method)
at java.util.zip.ZipFile.<init>(ZipFile.java:114)
at java.util.jar.JarFile.<init>(JarFile.java:133)
at java.util.jar.JarFile.<init>(JarFile.java:97)
at org.apache.catalina.startup.TldConfig.tldScanJar(TldConfig.java:451)
at org.apache.catalina.startup.TldConfig.execute(TldConfig.java:305)
at org.apache.catalina.startup.TldConfig.lifecycleEvent(TldConfig.java:734)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4308)
at org.jboss.web.tomcat.service.deployers.TomcatDeployment.performDeployInternal(TomcatDeployment.java:321)
at org.jboss.web.tomcat.service.deployers.TomcatDeployment.performDeploy(TomcatDeployment.java:146)
at org.jboss.web.deployers.AbstractWarDeployment.start(AbstractWarDeployment.java:464)
at org.jboss.web.deployers.WebModule.startModule(WebModule.java:118)
at org.jboss.web.deployers.WebModule.start(WebModule.java:97)

It looks like the problem is that TldConfig.tldScanJar is trying to open a directory that it thinks is a JAR file. The directory is created in server\default\tmp when the EAR is exploded during deploy.