Mokita - 7:46 am on Oct 18, 2011 (gmt 0)
Under what circumstances do we most often find people looking for nonexistent files in our webspace?
This issue is not about "people" asking for non-existent files, nor even any sort of bot asking for the image. I'd lay a huge bet that none of our human visitors have any remote idea that the png is being requested on their behalf.
Plus, I have never seen "bot-like" activity ask for it either. It is always human-visit related.
It appears to be some sort accidental mal-programming - either by GTB or MSIE, or an unholy mix of the two.
What is most disappointing, is that this issue was first reported more than a year ago, but it seems that neither G. nor M$ has done anything to either identify, own or rectify the problem.