Hi Emmanuel, since several Debian Med package depend from aether-ant-tasks I had a look whether I can help. I started with some polishing in Git (set Vcs fields, Standards-Version, debhelper, cme) but for the real problem I can only confirm that I can reproduce the issue. However, since the packaging looks pretty normal to me I suspect that the issue might be rather caused by javahelper than by the package itself.
Unfortunately I can not be of more help here. Kind regards Andreas. -- http://fam-tille.de