Since you are using Flash memory target the ROM image is created by default.
I suspect that the problem might be caused by incorrect ROM image starting address. This could cause that your code is physically flashed at different address than expected and call to main() generates invalid instruction exception.
I'd suggest you to change the ROM image addresses according to new starting address of internal_flash segment:
1) enter "Internal_FLASH" target Project setting (Alt +F7)
2) select "EPPC Linker" settings under the "Linker" node
3) change "RAM Buffer Address" and "ROM Image Address" both to the same new starting address (0x00100000)
For more information about ROM image I'd invite you to see Build Tools documentation usually located
here: "<CodeWarrior Home Dir>\Help\PDF\Power Architecture Build Tools Reference.pdf" - section "Building a ROM Image"