The modified pom.xml after mvn appfuse:full-source contains a duplicated modules tag:
<modules>
<module>core</module>
<module>web</module>
</modules>

How to reproduce it:
--------------------
$ mvn archetype:generate -B \
-DarchetypeGroupId=org.appfuse.archetypes \
-DarchetypeArtifactId=appfuse-modular-spring-archetype \
-DarchetypeVersion=2.1.0-M2-SNAPSHOT \
-DgroupId=es.xxx.app \
-DartifactId=modular-spring \
-DarchetypeRepository=http://oss.sonatype.org/content/repositories/appfuse

$ cd modular-spring

$ mvn org.apache.maven.plugins:maven-eclipse-plugin:2.6:eclipse
(mvn eclipse:eclise does not work)

$ mvn appfuse:full-source

$ mvn install
[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[ERROR] FATAL ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Error building POM (may not be this project's POM).


Project ID: unknown
POM Location: e:\var\workspaces\appfuse\modular-spring\pom.xml

Reason: Parse error reading POM. Reason: Duplicated tag: 'modules' (position: ST
ART_TAG seen ...</properties>\r\n <modules>... @400:12) for project unknown at
 e:\var\workspaces\appfuse\modular-spring\pom.xml