Well...one point of modifying the firmware of anything is to fix bugs. You see, many of the wonderful electronics we enjoy.....ok ALL OF THEM....were created by man, who is imperfect (not as imperfect as woman though). Therefore, they (the electronics) occasionally have problems and bugs are reported. Top programmers rush to the scene and debug thousands if not MILLIONS of lines of code and write a patch to fix the bugs. Then they roll them out in a firmware upgrade. This is usually denoted in the firmware version number by incrementing the last number of the version number by 1. (of course, sometimes they use letters instead)