When I run my test integrated with DBUnit throught DBUnitSeamTest, hbm2ddl is executed after dbunit population.
This causes a NoSuchTableException.
How could I extend the DBUnitSeamTest class to solve this issue?
This sounds very wrong. Hibernate should boot (and run hbm2ddl) before DBUnit does it's population. What version of Seam? Take a look at the seamdiscs example, it uses DBUnitSeamTest and hbm2ddl.