BIG hint from my side:
do not rename the file as original.so.something, but change the part before the '.so' ending.
Not sure if Harmattan acts the same way, but I had big troubles under Fremantle having two versions of a lib with name 'original.so' and 'original.so.bkp' or 'original.so_bkp'. After naming it to 'original_so.bkp' everything was okay.
Again: maybe above is okay, but I will not forget this anymore (happened twice to me ).