You can find the full source code for this website in the Seam package in the directory /examples/wiki. It is licensed under the LGPL.
you are using a <h:selectManyListbox />, a <h:selectManyCheckbox /> or a <h:selectManyMenu /> and are getting an exception like:
java.lang.IllegalArgumentException: Cannot convert Foo@3960f3 of type class Foo to class Foo_$$_javassist_219
you are using a sort of <h:select.../> with lazy initialization on the entity property being selected and not seeing the correct value being selected.
Then you should upgrade to the JSF RI 1.2.08 as it fixes this issue. If you are using JBoss AS, then take a look at this tip.