After moving from 7.3.3 to 7.4
    [junit] ...........F..............................
    [junit] .........................................
    [junit] .............................
    [junit] Time: 20.137
    [junit] There was 1 failure:
    [junit] 1)
testTransactionIsolation(org.postgresql.test.jdbc2.ConnectionTest)junit.framework.AssertionFailedError: expected:<8>
butwas:<2> 
    [junit]     at
org.postgresql.test.jdbc2.ConnectionTest.testTransactionIsolation(ConnectionTest.java:271)
    [junit]     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native
Method)
    [junit]     at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    [junit]     at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    [junit] FAILURES!!!
    [junit] Tests run: 111,  Failures: 1,  Errors: 0
It's because PG sends back "serializable" instead of "SERIALIZABLE" now.
Attached fix.
Cheers,
Kim