vaadin multi-modules project

Hi all,
i just want to know : Could we separate the domain of a project into a separate module it will be packaged into a jar file and it will hold the persistence configuration then it will be referenced by other modules.
I’am trying to do that but it seems impossible for me i have a project bgserver wich contain 2 modules a bgserver-core module, bgserver-productmanagment here is the spring-roo code to so:
using the spring-roo shell i create the project and the two modules like this :

project --projectName bgserver --topLevelPackage com.bgserver --java 6 --packaging pom
module create --moduleName bgserver-core --topLevelPackage com.bgserver --java 6 --parent com.bgserver:bgserver:0.1.0.BUILD-SNAPSHOT
persistence setup --provider HIBERNATE --database MYSQL --databaseName test--hostName localhost --userName user--password password
entity jpa --class ~.domain.Region --testAutomatically
field number --fieldName regionId --type long --notNull --column regionId 
field number --fieldName  countryId --type long --notNull --column countryId 
field string --fieldName name --notNull --sizeMax 255 --column name 
field string --fieldName regionCode --notNull --sizeMax 24 --column regionCode 
module focus --moduleName ~
module create --moduleName bgserver-productmanagement --topLevelPackage com.bgserver.web --java 6 --parent com.bgserver:bgserver:0.1.0.BUILD-SNAPSHOT
pgp trust --keyId 0xBF0451C0
download accept terms of use
addon list 
addon install bundle --bundleSymbolicName com.vaadin.spring.roo.addon
vaadin setup --applicationPackage ~.web --baseName bgserver --themeName bgserver --useJpaContainer true
dependency add --artifactId com.bgserver --groupId bgserver-core --version 0.1.0.BUILD-SNAPSHOT
module focus --moduleName ~

now i right click the pom of the parent project and run “maven install” so that the inter-dependency between the two modules is configured
then i want to generate the UIs for the bgserver-core entities but i cant for exempl see what happen when i try the following commands:

roo>module focus --moduleName bgserver-productmanagement 
bgserver-productmanagement roo>vaadin generate all --package ~.web.ui --visuallyComposable true
bgserver-productmanagement roo>Command 'vaadin generate all --package ~.web.ui --visuallyComposable true' was found but is not currently available (type 'help' then ENTER to learn about this command)
bgserver-productmanagement roo> hint
Roo requires the installation of a persistence configuration,
for example, JPA or MongoDB.

For JPA, type 'jpa setup' and then hit CTRL+SPACE three times.
We suggest you type 'H' then CTRL+SPACE to complete "HIBERNATE".
After the --provider, press CTRL+SPACE twice for database choices.
For testing purposes, type (or CTRL+SPACE) HYPERSONIC_IN_MEMORY.
If you press CTRL+SPACE again, you'll see there are no more options.
As such, you're ready to press ENTER to execute the command.

Once JPA is installed, type 'hint' and ENTER for the next suggestion.

Similarly, for MongoDB persistence, type 'mongo setup' and ENTER.

up to this stage i can only run the "vaadin setup… "command or the “vaadin widgetset create command” ( i want to use a widgetset for my forms). when i run the command “vaadin widgetset create” it take time to compile and when it finish an error shows off in the pom file

Plugin execution not covered by lifecycle configuration: com.vaadin:vaadin-maven-plugin:1.0.1:update-widgetset (execution: default, phase: process-classes)

and when i run the command

persistence setup --provider HIBERNATE --database MYSQL --databaseName branguard --hostName localhost --userName branguard --password branguard

every thing goes well and i can run for example the "vaadin addon install --artifactId ckeditor-wrapper-for-vaadin
vaadin widgetset create " but when i deploy the bgserver-productmanagement module to the server i got an execption saying that there is a conflict between the persistence file of the bgserver-core module and the bgserver-productmanagement module
Can any one help me please i need this to beed done soon i already wasted two days trying to figure out how to do it