Does your Seam 2 app undeploy-redeploy in an infinite loop? Congratulations! You have just come across one of the well-known-for-years-and-easy-to-fix-though-ignored bugs of JBoss AS 5!
.*dia files are generated by JBoss Tools when editing faces-config.xml and pages.xml with the visual editor. JBoss AS 5 screws up when he finds such files….
Those files are listed neither in Package Explorer, nor in Project Explorer; they are listed in the Navigator view though.
Here’s the fix: remove all *.jsfdia and *.spdia files from your project or from the exploded .war