THE MYSTERY HAS FINALLY BEEN SOLVED.
I think I owe it to everyone who tried to help me to let him/her know that I have finally found the cause of the wolf tone that had been bothering me since I got my new (used) guitar. No, it was not the B string (I have replaced it a few more times since my last post) nor my guitar that was causing the problem. It was my electronic tuner!!! I found out today that it was giving false readings for the B and the two E strings (i.e., these strings were actually tuned higher than what the tuner was showing). To correct the anomaly, I tuned the A's on all six strings and the result was spot-on. The wolf tone (or sympathetic buzz) is now completely gone. Since my tuner is not accurate with open strings, I will follow this alternate tuning procedure from now on. Or maybe, I'll get myself a new and better tuner.
If anyone is experiencing weird notes, please check your electronic tuner first before spending money on new strings, etc., as I did.
Again, thank you all very much for your comments and suggestions. Best regards.
El Baroda, Sydney
I shall pass this way but once. Any good, therefore, that I can do, or any kindness that I can show to another person, let me do it now. Let me not defer or neglect it, for I shall not pass this way again. - Anon.