JDBC connections to 9.1

I'm getting JDBC exceptions when I try to connect to 9.1 (master) with
the postgresql-9.0-801.jdbc3.jar I don't have this issue with 9.0.

There is nothing obvious at http://jdbc.postgresql.org or in the 9.1
alpha release notes that indicate a newer JDBC driver will be required.

Have other people seen similar issues?

If 9.1 does require a JDBC driver upgrade then it would be good if an
updated driver was posted before we start encouraging people to test
their applications with the beta.

Caused by: org.postgresql.util.PSQLException: Protocol error. Session
setup failed.
at
org.postgresql.core.v3.ConnectionFactoryImpl.readStartupMessages(ConnectionFactoryImpl.java:496)
at
org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:112)
at
org.postgresql.core.ConnectionFactory.openConnection(ConnectionFactory.java:66)
at
org.postgresql.jdbc2.AbstractJdbc2Connection.<init>(AbstractJdbc2Connection.java:125)
at
org.postgresql.jdbc3.AbstractJdbc3Connection.<init>(AbstractJdbc3Connection.java:30)
at org.postgresql.jdbc3.Jdbc3Connection.<init>(Jdbc3Connection.java:24)
at org.postgresql.Driver.makeConnection(Driver.java:393)
at org.postgresql.Driver.connect(Driver.java:267)
at java.sql.DriverManager.getConnection(DriverManager.java:620)
at java.sql.DriverManager.getConnection(DriverManager.java:200)
at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.mozilla.javascript.MemberBox.invoke(MemberBox.java:161)
... 14 more