I recently had my clutch replaced and a new battery put in. Within a month my regulator/rectifier burnt out of it. So, I purchased a new one. After 2 weeks that one burned out also. I replaced the stator, the battery again, and the wiring harness. Now, this is my 3 regulator/rectifier that had burnt out on me. After the second one, I was told to have it mounted outside of the frame. That only lasted a week and it had burnt out again. Everything I purchased was brand new, so I was wondering if someone could help me find out the problem.
[answer in progress]
One of the reasons regulators burn out is overheating. That is why people put it outside the frame on some bikes to get better airflow around them, and out of the cooker. However, given that you had done that, it must be other reason. I would suspect connections, but then again, you had replaced the harness (seems a bit rash, replacing major parts willy-nilly).
But here is something about regulator ground (via fireblades.org):