plugin ends up in wrong directory when deployed with sftp

> when trying to deploy my plugin on my plugin on my own maven repository
> using the latest 1.5.1 Artifact Plugin using sftp and a private key,
> all seems to go well:
>
> plugin:repository-deploy:
> [echo] Deploying...
> Will deploy to 1 repository(ies): freehep
> Deploying to repository: freehep
> Uploading to freehep/poms/freehep-jas-plugin-1.0.pom:
> .................... (6K)
> Will deploy to 1 repository(ies): freehep
> Deploying to repository: freehep
> Uploading to freehep/plugins/freehep-jas-plugin-1.0.jar:
> .................... (2K)
> BUILD SUCCESSFUL
>
> however, the pom and jar files (including the md5 and sha1) ended up in:
>
> 'freehep' rather than in the subdirs 'freehep/plugins' and 'freehep/poms'
>
> it seems the type is forgotten...