General :: -fPIC Compiler Option Doesn't Let Application Initialize

My application is developed using GCC and an binary executable created out of it which initializes successfully. By initialization, I meant all the threads in the application are created and I get the required response from the executable. There was a need to create a .so file out of my application instead of binary executable, as it needs to be integrated with another .so file to create a final patch. So we used -fPIC compiler option and created a .so and also an binary executable. But with -fPIC included, the executable fails to initialize at all. It executes some instructions in the main program, before finally haulting down with a " Program received signal SIGSEGV, Segmentation fault." error. And it always fails at the same faulty address which points to nothing in my application code. What is that -fPIC adds to the code, which makes my code fail with strange behaviour.