Created attachment 44102 [details] Link to Testcase (Usage of !important) Shows last defined property assignment, even if overwritten with !important, when selecting an element in the element view of the inspector. The computed style for that element is shown correctly.
The link to testcase is dead (404). I also believe this has been fixed a while ago. Please reopen and specify a valid testcase if this still works wrong.
I just filed bug 62656 on a similar issue.