I found an issue while trying to use the @Digits hibernate validator which happens to resolve an issue very cleanly for me validating a backing bean with a Long attribute. I get a class not found exception in the app server using the jboss hibernate annotation libs for the 'org.hibernate.validator.Digits' class b/c it is not there. The version in JBOSS AS 4.2.1 is using version 3.2.1 of hibernate-annotations.jar and the version in SEAM 2.0 GA is using v3.3 where the validator classes have apparently be refactored into another jar called hibernate-validator.jar (apparently version 3.0 based on the MANIFEST.MF) which is altogether not present in jboss 4.2.1, but it is present in SEAM 2.0 GA. There are 2 possible solutions that I can think of: 1) I could replace the version of of hibernate-annotations.jar and add hibernate-validator.jar in my local copy of jboss AS, however, that only fixes me locally. 2) I could introduce these jars into my ear file and possibly run into class collisions between the annotations and validation jars in the AS. Regarding option 1, as for operations protocol, slipping in jars and swapping out jars in our production app server requires an act of congress. Regarding option 2, I don't want to deal with class collisions between my ear file and the AS. How do I a mitigate this problem of hibernate-annotation versioning between SEAM 2.0 & Jboss AS 4.2.1? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4104347#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...