With facelets it's recommended not to use JSTL except if you really need to and you understand how it will interact with facelets. Certainly for the above you would be much better off using the rendered attribute
After reading Facelets API, Ifound it is supposed to support IF tag. Then I checked dvdstore example and found I was using wrong namespace definition (I copied it from somewhere in the internet). Now it is working very fine.
xmlns:c="http://java.sun.com/jstl/core" is the right namespace
not xmlns:c="http://java.sun.com/jsp/jstl/core" as I had previously.
Thank you for quick reply and for SEAM examples, they are great source!