post the structure of your deployed application, in particular show where the cz.mydomain.CoreELFunctions class is
Nice to read you again. My app is archived as EAR.
app-ejb.jar/ <--- 2nd try CoreELFunctions
...contains Seam components/actions/business logic
classes/ <--- 1nd try CoreELFunctions
The problem is that EL functions work when rendering page but not after posting actions.
The correct place is in WEB-INF/lib but i know we had issues with this when getting Seam running on JBoss AS 4.2. I would recommend upgrading to Seam2 or running 1.2.1 on AS 4.0.5
we'd the same issue in the past,
downgrading jboss fixed it
same goes for upgrading seam version