So I repaired the .zip file using one of the tools from the link and it opens now on my computer but it's just a part of what I had uploaded on ftp... So I guess it wasn't zipped or downloaded correctly. I actually created a few of these files before I realised that they are not downloading instantly but getting created on ftp and I downloaded all of them to have a backup plan (heh) but they all have the same problem (and the same size which made me believe it's ok)
Do you confirm then that after deleting the old account all the files were deleted permanently?
I guess I'm having a really bad day because I don't have any source code backuped locally since it's not really that important site and I made it some time ago, but it was nice to have it around.