Good news, my gamebuino is working.
You were right, I've only to format again the µSD card in FAT.
The first time I've formatted it, it was on a computer with Win8.1 and I've done a really big mistake, because I've thought that in the format program, "FAT" mean "FAT16", but as it's a x64 OS, "FAT" mean "FAT32".
Oops
But the good news, as I have always a very old computer with Windows XP, I've been able to format again and copy all original files.
Maybe you can create a FAQ to summarize all these small problems that many people can encounter.
And a small resume about what is the bootloader and how Gamebuino works (loader.hex loaded into gamebuino and other programs stored into µSD due to the small memory of Gamebuino, and dynamically loaded into Gamebuino memory replacing the loader, ...).
I don't remember having read a similar information into WIKI or the forum.
Sorry if I missed something (I'm a newbie in Arduino and Gamebuino
).
I've also seen the topic about the
alternative bootloader by Jonnection.
I'll read it and check if I'm able to load it
I consider my problem solved.
Thanks for the help.