Spring transaction annotation throws Rollback Exception for tcserver 7.0

Question

I have a scenario, where I am using Spring Transaction management with JDBC and tcServer 6.0. Below snippet code

@Transactional(rollbackFor = Throwable.class)
public int dropDynamicModelTables(String namespace) {
 ....

some DML operations are performed and some of the tables are dropped. The above code was working absolutely fine , but when I use tcServer 7.0 version I get Exception as

org.springframework.transaction.UnexpectedRollbackException: Transaction rolled back because it has been marked as rollback-only

Does anyone have any idea why am I facing the problem. The only change is from tcServer 6.0 to tcServer 7.0. Is it issue with application or with the Server.