i was working on PIC 16 family, and using Mikro C PIC cross compiler, my code worked well until certain point, after adding any line of code after this point microcontroller behaves strangely, i started to suspect my code which is being tested many times. finally the reason was Mickro C PIC doesnot support automatic memory banks switching for pic 12 and 16 family. I learned not to use non official tool chain after that.