309791 - Absolutely positioned block element with opacity layered over Flash causes Flash object to disappear

Status: RESOLVED DUPLICATE of bug 309790

(Firefox :: General, defect)

Description

[Aaron Fowler]

User-Agent:       Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8b4) Gecko/20050908 Firefox/1.4
Build Identifier: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8b4) Gecko/20050908 Firefox/1.4

Layering an absolutely positioned block element with CSS opacity of less than 1
over a Flash object causes the the Flash object to become invisible.  The Flash
object must have its wmode set to transparent.  Removing the opacity results in
correct rendering.  Removing the wmode=transparent results in a visible Flash
object, but the block element is shown behind it, even if the z-index of the
element is higher than the Flash object.

Opacity On: <a
href="http://tisch.nyu.edu/page/opacityon">http://tisch.nyu.edu/page/opacityon</a>

Opacity Off: <a
href="http://tisch.nyu.edu/page/opacityoff">http://tisch.nyu.edu/page/opacityoff</a>

This was first noticed on the following page, where the "About Tisch" dropdown
menu slightly overlaps the Flash movie: <a
href="http://www.tisch.nyu.edu/">http://www.tisch.nyu.edu/</a>

This bug does NOT apply to Firefox 1.0.x on Mac or Windows. This only applies to
Firefox 1.5 on Mac OS 10.4.2.  I haven't tested on Windows or other systems.

Reproducible: Always

Steps to Reproduce:
1. Embed a Flash object with wmode=transparent in page
2. Absolutely position a block element over the Flash object
3. Set CSS opacity on block element to less than 1

Actual Results:  
The block element is shown correctly, but the Flash object is invisible.  The
Flash object still has clickable links and the sound works.

Expected Results:  
The block element should be layered (with opacity) over the visible Flash object.

Comment 1

[Frank Wein [:mcsmurf]]

*** This bug has been marked as a duplicate of 309790 ***