Gen7 - Impossible to upload firmware (no replies)

Hi !

I've started building a RepRap Prusa Mendel, and i'm using Gen7 for the electronic...

My trouble is that I can't upload a firmware to the Gen7... The upload takes a long time and in about 10 minutes there are a couple of error (e.g. Time out).
[puu.sh]

I read that it could be an autoreset problem, but even though I reset manually just before the upload, I have the same problem...

And I tried with Teacup, Marlin, and Repetier...

Anyone as an idea ?

Thanks (and sorry for my english, I'm french )