Why does the Calculate use a Duplicate version of Conkyforecast ?

I installed conkyforecast and I see now

[D] app-admin/conkyforecast
     Available versions:  ~2.15[1] ~2.20 ~2.24
     Installed versions:  2.15[1](02:07:14 AM 09/14/2013)
     Homepage:            https://launchpad.net/~conkyhardcore
     Description:         Conky weather forecast script with support for language files

I also noticed that this Version is in the calculate overlay… Why?

I can only suppose that ebuild has been added when the package was not yet in portage or this version was newer than the ones that had to portage

Thank You
I guess for now that will do…