I have problems with newest bitstream too.
1st: I renamed files to new name order, at boot no one except bitstream found
2. I added files in old name order and left on card both, found, unchanged ROM, old and new named same files - checksum incorrect, C65 mode works in MLM only, I mean broken Editor, C64 mode works ok
3. I left there all, only exchanged bitstream to old and:
Mega 65 works
What I did wrong???