JDK 1.5 java.lang.Enum Buid Failure using Maven 2.0.8

[William Hoover]

I am using JDK 1.5 / Maven 2.0.8 and am attempting mvn clean install on a 
simple project that contains the following snippet:

...

public final Class<? extends Enum<? extends IDTOPhase>> 
getDTOPhaseLifeCycleStrategy(){
        return someEnumClass;
}

...

for(java.lang.Enum<? extends IDTOPhase> phase : 
getDTOPhaseLifeCycleStrategy().getEnumConstants()){
        ...
}

...

The problem is that this compiles w/o a problem using ANT (or Eclipse build), 
but fails using Maven. I get the error:

... incompatible types
found : java.lang.Enum<? extends IDTOPhase>
required : java.lang.Enum<? extends IDTOPhase>

I even set the maven-compiler-plugin to ensure compilation in 1.5

<plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>2.0.2</version>
        <configuration>
                <source>1.5</source>
                <target>1.5</target>
        </configuration>
</plugin>

Any clue??? Thanks!