User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.1; .NET CLR 2.0.50727; ffco7) Gecko/2008070208 Firefox/3.0.1 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.1; .NET CLR 2.0.50727; ffco7) Gecko/2008070208 Firefox/3.0.1 Someone broke the ability of firefox to properly display transparencies and subwindows with overlays. To see what I'm talking about visit the site with 2.0 first. You only need glance at the top center of the default page. Then do the same with firefox 3.0. You'll immediately see a difference. Reproducible: Always Steps to Reproduce: 1. Visit www.whoisfollowingme.com with firefox 2.0 2. Look at top, center of main page and see notes that accompany satellite overview. 3. Repeat with firefox 3. Actual Results: With firefox 3.0, no comment layers appear to the right of the photo. (There are also two comment layers missing from below the image.) Expected Results: With firefox 2.0 the comment layer on the right (light blue background) begins, "Note that I drove a circuitous route ...". A comment layer below the image says (light blue background), "Be sure to read text in this section." A comment layer below the image says (red background), "To see next slide, click on thumbnails below (from left to right)." Bug is immediately apparent and should take you all of a minute to see, if visit the page with both firefox 2.0 and then firefox 3.0.

A minimized testcase would be great

What is a minimized test case?

I tried to produce a test case but the page cannot be rendered accurately offline.

This may help you: Since I built the website in question I can tell you that the layers briefly flash and then disappear. All you should have to do to find the bug is compare layer rendering in version 2 and see what changed in version 3. This page works with firefox 2.0 and you already have the code to fix it. You just have to undo whatever was done.

Note that layered comments are missing from image.

>This page works with firefox 2.0 and you already have the code to fix it. You >just have to undo whatever was done. Sorry but that is a little bit funny. Between Firefox2 and Firefox3 are 3 years (!) of development with thousands of changes from hundred of different developers. I see the difference but that doesn't mean that it's a bug in Gecko (the rendering Engine).

Yes, it certainly does. Listen, if you don't want to fix your software that Internet Explorer 5.5+, 6 and 7 and Firefox 2.0 render correctly, then don't. But the idiotic position that the rendering code is not broken is simply wrong.

>Yes, it certainly does. Listen, if you don't want to fix your software that To make it clear : a) I never told you that a bug in Gecko should not be fixed b) I will not fix this bug c) It's not my software d) I never told you that the html/JS is wrong, i only told you this it's unclear if this is a bug in Gecko or if this is a bug in the html/JS. e) I told you that it's not possible to just look at the changes between FF2 and FF3 to find the cause of this (not without more information like a minimized testcase) I only asked for a minimized testcase that you or someone else can provide to identify the problem.

Its very difficult to judge completely obfuscated source code ;-). So whoever wants to look at this again view:source first.

This is a regression from bug 317375 (25 Jan 2006).

I didn't get this testcase by traditional testcase reducing, because that didn't work. I rather looked with the dom inspector at the relevant nodes that were causing the problem. I think this is basically the situation. In Firefox 2, this gives a red box as result, while Firefox 3 gives a green box as result. The behavior of Firefox 3 is the correct one, in this case. Note that with the website in question, the layout problem is there to be seen in Opera9.5, Safari and Google Chrome. Which also seems to suggest that the website is doing something wrong.