Please indicate when margin collapsing is in effect in the Web Inspector. Here's two places it could possibly go: - In the Metrics panel, perhaps by putting the margin number in italics or adding a symbol - In the Styles panel under Computed Style, by adding "(collapsed)" or "(merged with parent)" to the appropriate margin property. I recently spent a long time trying to track down a strange bug in my CSS, and this feature would help tremendously with that!
*** This bug has been marked as a duplicate of 17223 ***