I have been using SO off-and-on for about a year now

I have dozens of answers and questions. My reputation is about 1500. I have never spammed or done anything that could potentially result in my being flagged as a problem (at least I think)

Yet, I am often forced to enter a captcha when posting. In the case that I create a question, then immediately edit it, I *always* see the robots from Flight of the Conchords. (btw, I don't like this show at all)

Why do I need to enter a captcha so often? Is there a reputation level where I won't be required to?