Thanks Jerry for your kind information. I have checked that thread and found this information "Check your audio hardware in Premier Preferences and under Default Device make sure that System Device Input/Output is not selected, I have it as Built in Line Output and Premier is back to normal both on playing and stopping."
After following the recommended fix, I have found that its not relevant to my problem of playhead stop delay and it didn't help. Actually I have closely seen that the delay is exactly 3 Frames from the moment I hit the Space bar from the keyboard to the moment the playhead actually stops playing the timeline. I would really appreciate some more help in this regard if you could point me some more things to check.
Thanks again for your kind help.