Gpm : Error when trying to download

Hello,

I installed grav yesterday on a osx 10.9 system and after some tweaking everything seems to be running pretty well... except the gpm.

When i try to install new plugin, themes or when i try to update the gpm doesn't manage to download, the error is:

Preparing to install Form [v2.13.3]
  |- Downloading package...    error                             
  |  '- Error while trying to download (code: 302): https://getgrav.org/download/plugins/form/2.13.3 
  |  '- 
  '- Installation failed or aborted.

It is happening either in the terminal or via the admin panel. I've tried to switch from fopen to curl in the configuration, and I've disabled the "Remote Verify Peer (SSL)". Do you know what I am doing wrong?

Thanks in advance,
Nicolas

Nobody has an idea?
I would really like to use grav, I like it a lot, but if I can't update easily, it is not really usable...
Thanks in advance for any hint!