Maven Proguard Libs

Olá!

Estou tentanto proteger um código fonte contra decompilação, com o Proguard, mas estou enfrentando problemas.
A configuração do plugin está assim:

<plugin>
    <groupId>com.github.wvengen</groupId>
    <artifactId>proguard-maven-plugin</artifactId>
    <version>2.0.11</version>
    <dependencies>
        <dependency>
            <groupId>net.sf.proguard</groupId>
            <artifactId>proguard-base</artifactId>
            <version>5.2.1</version>
        </dependency>
    </dependencies>
    <executions>
        <execution>
            <phase>package</phase>
            <goals>
                <goal>proguard</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
        <proguardVersion>5.2.1</proguardVersion>
        <obfuscate>true</obfuscate>
        <includeDependency>true</includeDependency>
        <injar>${project.build.finalName}-jar-with-dependencies.jar</injar>
        <outjar>${project.build.finalName}-jar-with-dependencies-obf.jar</outjar>
        <outputDirectory>${project.build.directory}</outputDirectory>
        <maxMemory>256m</maxMemory>
        <options>
            <option>-keep public class br.com.principal.** { public *; public static *; }</option> 
            <option>-allowaccessmodification</option>
            <option>-dontoptimize</option>
            <option>-dontskipnonpubliclibraryclasses</option>
            <option>-dontskipnonpubliclibraryclassmembers</option>
            <option>-dontwarn javax.activation.**</option>
            <option>-dontwarn org.apache.commons.logging.**</option>
        </options>
        <libs>
            <lib>${java.home}/lib/rt.jar</lib>
            <lib>${java.home}/lib/javaws.jar</lib>
            <lib>${java.home}/lib/jce.jar</lib>
        </libs>
    </configuration>
</plugin>

O principal, é que o jar gerado ofuscado, “apaga” as bibliotecas(jars) necessários.

O segundo problema, é que preciso adiconar os “-dontwarn”, mas estas bibliotecas estão em meu pom.xml. Se eu removo a diretiva, apresenta erro:
[proguard] Warning: library class com.sun.istack.internal.ByteArrayDataSource extends or implements program class javax.activation.DataSource
[proguard] Warning: library class com.sun.xml.internal.bind.v2.runtime.unmarshaller.Base64Data$1 extends or implements program class javax.activation.DataSource
[proguard] Warning: org.apache.poi.util.CommonsLogger: can’t find referenced class org.apache.commons.logging.LogFactory
[proguard] Warning: org.apache.poi.util.CommonsLogger: can’t find referenced class org.apache.commons.logging.Log

Alguém sabe como solucionar isso? Obrigado

DRauber