Tomcat + Datapool + postgres

Ola, tenho uma aplicação web utilizando datapool, mas na hora de criar a conexão com o postgres (9.1) recebo uma exception.

driver: postgresql-9.1-903.jdbc4.jar
java: 1.7
Tomcat 7

o driver está entro da pasta WEB-INF, mas não está dentro da pasta lib do Tomcat.

context.xml

<?xml version="1.0" encoding="UTF-8"?>
<Context antiJARLocking="true" path="/1">

	 <Resource
	 auth="Container"
	 driverClassName="org.postgresql.Driver" 
	 maxActive="100"
	 maxIdle="30"
	 maxWait="10000" 
	 name="jdbc/tecWebSoft-DS" 
	 url="jdbc:postgresql://pgsql.tecwebsoft.com:5432/tecwebsoft1"
	 username="tecwebsoft1"
	 password="32665701" 
	 type="javax.sql.DataSource"
	 />
	 
</Context>

web.xml

<resource-ref>
		<description>Orion Datasource</description>
		<res-ref-name>jdbc/tecWebSoft-DS</res-ref-name>
		<res-type>javax.sql.DataSource</res-type>
		<res-auth>Container</res-auth>
	</resource-ref>

exception:

java.lang.AbstractMethodError: org.postgresql.jdbc2.Jdbc2DatabaseMetaData.getDatabaseMajorVersion()I
	at org.apache.tomcat.dbcp.dbcp.DelegatingDatabaseMetaData.getDatabaseMajorVersion(DelegatingDatabaseMetaData.java:249)
	at org.hibernate.dialect.resolver.DialectFactory.determineDialect(DialectFactory.java:130)
	at org.hibernate.dialect.resolver.DialectFactory.buildDialect(DialectFactory.java:96)
	at org.hibernate.cfg.SettingsFactory.buildSettings(SettingsFactory.java:117)
	at org.hibernate.cfg.Configuration.buildSettingsInternal(Configuration.java:2863)
	at org.hibernate.cfg.Configuration.buildSettings(Configuration.java:2859)
	at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1870)
	at org.hibernate.ejb.Ejb3Configuration.buildEntityManagerFactory(Ejb3Configuration.java:906)
	at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:57)
	at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:63)
	at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:47)

Por favor, não duplique tópicos:
http://www.guj.com.br/java/296336-tomcat--datapool--postgres#1574216

Tópico trancado.