Before you vote to close: Yes, I've seen this question and this blog post - and no, they don't help.
I just noticed my "Accept Rate" on Meta today is horrible. Before reviewing my questions, accepting one answer, and deleting a "closed as duplicate" thread, my rate was around 30%. Now, I've gotten it up to 50% but that still didn't seem right.
Then, I took a closer look at the questions I have here. There's 9 in all, only 4 of which have any answers. So, of course my "Accept Rate" would be around 50% of all the questions I've posted - but even that didn't seem just.
Next, I started writing this question and got the above-linked question in the "Related Questions" box. I started reading through, and it still appears to me that my current "accept rate" is not correct. Of my 9 questions, every question that has been answered has an accepted answer. So, my "Accept Rate" should be 100%
Additionally frustrating is that the majority of my unanswered questions are feature-request or bug - but that is another issue.
I haven't yet tested this on any of the other sites, but will be following up on it shortly.