@Faizan, you said it. I forgot to mention the 4th gear. My guess is something, at that speed range, make this happens...may be the foundation on which gear assembly rest...or something!!!. Let me browse the service manual.
Key Problem: One friend of mine offered a useful advise of making an ordinary key for opening doors and use only "KEY" for ignition. This will save the wear and tear and ALLAH forbid if you lose "KEY" still you have access to the inside of your car without starting it. I asked on 3S dealer and got 4000 and 10000 for normal and remote keys respectively. BTW, add another 2500 for programming.
I will post results my advances on this KEY problem