Custom DataSource expression dependency in Jaspersoft Studio

[maureyeslopez]

I'm trying to create and compile a report in Jaspersoft Studio 5.5.0. I've implemented a custom DataSource on a different project and created a jar that added to my reports project build path. I've defined the Data adapter using my custom datasource and now I want to use it in the <dataSourceExpression> tag for a table component.
This is the generated XML:
<datasetRun subDataset="testDS" uuid="89b0a627-487b-4a0c-96b9-ca7c909c3663">
        <dataSourceExpression><![CDATA[new CustomDataSource()]]></dataSourceExpression>
</datasetRun>

The problem is that I can't compile it (the error is "CustomDataSource cannot be resolved to a type").
I also have the Studio installed as a plugin in my Eclipse, where I've the sources of the project that contains the Datasource and works ok there, but I'd prefer to work in the Jasper Studio and without the sources.

Am I missing something? Any hint??

Thank you in advance for any help
Mauricio