Jailbroke iphone4 has bad audio and blue tooth connections?

Had bad audio problems and also bad blue tooth connections and audio. Had to hold iphone up to my bluetooth ear piece for it to kind of work. So I got upset today and restored iphone. Guess what It now works fantastic. I can actually use it to communicate with out people complaining about crackling noises ect and audio breaks. I can also now go upstair with bluetooth earpiece and leave Iphone on first floor while I talk or listen to music on iphone. I almost sent it in for repair. Not sure what caused it while it was jailbroke .