I solved the same error with
<dependency>
<groupId>com.sun.xml.parsers</groupId>
<artifactId>jaxp-ri</artifactId>
<version>1.4.5</version>
<scope>runtime</scope>
</dependency>
if it matters, the other libs I had were
<dependency>
<groupId>org.springframework.ws</groupId>
<artifactId>spring-ws</artifactId>
<version>2.1.0.RELEASE</version>
<classifier>all</classifier>
</dependency>
<dependency>
<groupId>com.sun.xml.messaging.saaj</groupId>
<artifactId>saaj-impl</artifactId>
<version>1.3.20</version>
<scope>runtime</scope>
</dependency>