The permissions are correct - rwxr x r x. The mmc card issue now makes sense, but the file not found error when it's in home is odd.

The Hello world app was compiled in scratchbox for the ARM processor. I checked it using the file command, and it works with the ARM emulator in scratchbox. I didn't use the maemo2.0 SDK, as this is a command line program - I didn't think it would need it. Perhaps this is my problem.