FAT32 fixed (more robust) :
* better definition about out of cluster range/end of cluster
* better detection of end of DirEntry (32bytes of zeros)

After more tests, I have a glitch after two days of no use. I think it is about the "hello sdcard, can I play with ?" sequence that seem not run at boot time.
So you can do this robust test : do load another dsk from OSD menu... and then it shall start ok.