question about rollback and SQLException

I received this exception when trying to rollback a transaction through the
Postgres JDBC driver (build106) used by a webapp running in Resin (2.0.6). I
have tried setting up the connection pool in my web.xml to use both
javax.sql.DataSource and javax.sql.XADataSource, but both give me this
exception:

java.sql.SQLException: ERROR:  parser: parse error at or near "qrollback"
        at org.postgresql.core.QueryExecutor.execute(QueryExecutor.java:131)
        at
org.postgresql.jdbc1.AbstractJdbc1Connection.ExecSQL(AbstractJdbc1Connection
.java:482)
        at
org.postgresql.jdbc1.AbstractJdbc1Connection.ExecSQL(AbstractJdbc1Connection
.java:461)
        at
org.postgresql.jdbc1.AbstractJdbc1Connection.rollback(AbstractJdbc1Connectio
n.java:1031)
        at
com.caucho.sql.UserConnectionAdapter.rollback(UserConnectionAdapter.java:470
)
        at com.gto.db.SqlTransaction.rollback(SqlTransaction.java:132)

Any idea what that means and how I can prevent it from occuring?

thx
andy kriger