I have disabled the seam transaction management in order to delegate all transaction management to Spring. In addition I have set transaction:no-transaction.
As a result I have a problem with s:convertEntity. According to the documentation s:convertEntity elements requires a transaction object.
The NoTransaction class just throws these nice UnsupportedOperationException when the entity converter tries to convert select item elements. So I would try to implement and register a custom implementation of AbstractUserTransaction that is more graceful!
Can somebody hint me into th right direction on how to register such a class that can be later used in components.xml.