maven doesnt recognize execution'a tag from build-helper-maven-plugin
===

Im trying to export resources (.java, .gwt.xml, .ui.xml) from project A to Project B with Maven. So in project A I write the following pom:

But when I run Install Maven I got this error:

    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
	<modelVersion>4.0.0</modelVersion>

	<parent>
		<groupId>com.pe.interbank</groupId>
		<artifactId>reactor</artifactId>
		<version>1.0.0</version>
		<relativePath>../reactor</relativePath>
	</parent>


	<properties>
		<path2>Reactor/pom.xml</path2>
		<path1>C:/Angelo/Workspace/MultipleGWTv2/Reactor/pom.xml</path1>
	</properties>

	<artifactId>transferencias</artifactId>
	<packaging>jar</packaging>
	<name>transferencias</name>

	<build>
		<resources>
			<resource>
				<directory>src/main/java</directory>
				<includes>
					<include>**/*.java</include>
					<include>**/*.gwt.xml</include>
				</includes>
			</resource>
		</resources>
		<plugins>
			<plugin>
				<groupId>org.codehaus.mojo</groupId>
				<artifactId>build-helper-maven-plugin</artifactId>
				<execution>
					<phase>generate-sources</phase>
					<goals>
						<goal>add-source</goal>
					</goals>
					<configuration>
						<sources>
							<source>src/main/java</source>
						</sources>
					</configuration>
				</execution>
			</plugin>
		</plugins>
	</build>

	<dependencies>
		<dependency>
			<groupId>org.codehaus.mojo</groupId>
			<artifactId>gwt-maven-plugin</artifactId>
			<version>2.4.0</version>
		</dependency>
		<dependency>
			<groupId>org.codehaus.mojo</groupId>
			<artifactId>build-helper-maven-plugin</artifactId>
			<version>1.7</version>
		</dependency>
	</dependencies>
</project>

The build could not read 1 project -> [Help 1]
 
The project com.pe.interbank:transferencias:1.0.0 (C:\Angelo\Workspace\MultipleGWTv2\Transferencias\pom.xml) has 1 error

 Malformed POM C:\Angelo\Workspace\MultipleGWTv2\Transferencias\pom.xml: Unrecognised tag: 'execution' (position: START_TAG seen ...</artifactId>\r\n\t\t\t\t<execution>... @36:16)  @ C:\Angelo\Workspace\MultipleGWTv2\Transferencias\pom.xml, line 36, column 16 -> [Help 2]

Any know why?

Thanks.