On Electronics SE I try to edit a question asked by another user. I click "edit", change the text and click "save". A message "please enter a comment" is displayed.
I use the newest and the freshest version of Chrome (also reproed in Firefox 4) with default settings and forms auto-complete. So I click into the edit box, a drop-down with previous comments appears and from the drop-down I select my most often used comment ("smaller version of images to reduce traffic" - that's the most typical reason why I edit questions on Electronics SE).
Now the edit looks like this:
there's the "briefly explain your changes" phrasing and also the comment I selected (right beneath "briefly explain" text) but the comment is displayed so faintly that it's barely visible. If I click "save" at this point the changes are saved together with my selected comment.
I guess there's a minor bug somewhere in the page code that fails to reset the "briefly explain" phrasing when an item is selected in browser auto-complete.