It looks like the deployment straight to the Maven repo has some issues.
All JARs are uploaded as text files instead of binaries. You can see
this with the following commands:
$ svn propget svn:mime-type
http://anonsvn.jboss.org/repos/repository.jboss.org/maven2/org/gatein/mop...
application/octet-stream
--> All fine, it wasn't using maven release:perform
$ svn propget svn:mime-type
http://anonsvn.jboss.org/repos/repository.jboss.org/maven2/org/gatein/mop...
(Returns nothing which means text file)
--> It was deployed with maven release:perform
Thomas.