OK, let me explain what I have done so far:
1. I modified main-pp.c (see attachment); the reason will become clear soon.
2. I used e200tool to boot my e280R into the vanilla BL.
3. I completely overwrote the Sansa bootloader with my custom built one
(i.e. using the modified main-pp.c file).
4. I also uploaded a copy of a decrypted mi4 of the rhapsody firmware to go
in the normal place in the hidden partition.

Now, the OF should load from the hidden partition, but I keep getting an
"Invalid file format!" error. Can anyone help?