You can always use programmatic transaction demarcation. Simply @Inject UserTransaction and turn off APE-provided by using @Transactional(NONE).
However I don't personally see a lot of value in such a test case, because what you are effectively testing is if ORM/DB code works with transactions and guarantees data consistency, which is not really your application responsibility anyway (that's what container provides).
Thnks! a lot! Bartosz...the Alpha6 seems like its better than Alpha5 jaja!...and whatever in i can help with APE it will be wonderful, especially in summer!!