548649 - Firefox main window loses mouse focus keyboard still works. Need to alt-tab x2 to get back!

Status: RESOLVED INCOMPLETE

(Firefox :: General, defect)

Description

[rlindroos]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6

FF 3.6 WinXP
All addons disabled and FF upgraded restarted and scanned for malware, virus, trojans, rootkits etc...
Mouse loses focus from Firefox mainwindow to a small 2x4 pixle window spawned by firefox. It's defiantly about FF. Why?
I downloaded Process Explorer from sysinternals and there is a little functions that allows you to identify a window with a process and guess what the process is firefox.

screenshot here

http://www.UploadScreenshot.com/image/50687/3566868

Reproducible: Always

Steps to Reproduce:
1.Start Firefox
2.Browse to any webpage
3.change desktop background to black so you can see the white window
4.make the window as small ass possible

Comment 1

[rlindroos]

Attachment: screenshot

Comment 2

[cyberrays]

I have the sane problem.  It is so annoying that I must use another browser until this bug is fixed.

Comment 3

[chris]

this started yesterday for me (3-1-10) after a flash game loaded (disabled flash to no avail), I was on 3.5.7 (I think, not sure, 3.5.8 installed this morning) I upgraded to 3.6 and still have the issue.  Have to use another browser, FF is unusable

Comment 4

[chris]

UPDATE: I did uninstall flash reboot and try again, worked for a little bit the quit.  It messed up immediately after I reinstalled flash but I don't think its related.  I have also uninstalled and reinstalled FF to no avail.  However what has been working is a different mouse.  My cordless was dead so I have been using a plug in USB for like a week, I finally put batteries in it today (3-2-10) and removed the USB and all is working after a reboot and has been for several hours, it had been quitting within a few minutes before.  I reinstalled flash and restarted FF and its still working....issue was only present in FF, everything else was fine.

Comment 5

[lasse.lindgren]

Confirmed, i have the same issue.

Comment 6

[David Gibbens]

My experience is slightly different, but matches the main description.  It also matches this http://support.mozilla.com/tiki-view_forum_thread.php?locale=ja&comments_parentId=649540&forumId=1 which appears in a Japanese forum. 
Key symptoms are:
The mouse doesn't appear to register clicks in the Firefox window - but it can vary how much of the window is affected.  I have had it where the mouse simply doesn't work at all. OR where you can select and click menu items and tool buttons but not the links on the webpage.  
NB in some instances even tne Windows toolbar at the bottom of the screen is affected so you can't click those.  But this behaviour only happens in Firefox - as soon as you alt-tab to another window everything works normally again.

As in the title of this bug, if you alt-tab out and then alt-tab back into Firefox, everything then works OK - but only until another you display another web-page, when the same problem re-emerges.  Makes Firefox unusable and I have been using it for 5 years.  Sad. Entering this from IE.
URL links are most affected and the links do not show up as links when you hover over them.

Have re-booted PC, reinstalled FF from fresh download - running 3.6.8. No improvement.
On Windows XP Professional fully up-to-date with automatic installation of updates.
Problem has emerged today on wifi in parents' house - normally on wifi in my own house or wired network. No software installed immediately before but did recently install HTC Sync 3.0 for HTC phone.
Optical mouse in long-term use. Have tried different usb ports to no avail.

Comment 7

[David Gibbens]

PS - on the "Japanese forum" posting it is only the first posting which matches my experience, not the others.  
The scroll-bar on the right doesn't work either but the web-page itself is working ie it is not frozen  - flash movies (or whatever they are)  still showing.

Comment 8

[Tyler Downer [He/Him]]

Reporter, Firefox 4.0.1 has been released, and it features significant improvements over previous releases. Can you please update to Firefox 4.0.1 or later, and retest your bug? Please also create a fresh profile (
http://support.mozilla.com/kb/Managing+profiles), update your plugins (Flash, Java, Quicktime, Reader, etc) and update your graphics driver and Operating system to the latest versions available. 

If you still continue to see this issue, please comment. If you do not, please close this bug as RESOLVED > WORKSFORME

filter: prefirefox4uncobugs

Comment 9

[Magnus Norddahl]

This bug also happens on my computer (Firefox 14.0.1, Windows 7 Ultimate 64 bit). You can consistently trigger it by surfing to http://youtube.com (or any other page containing flash) and during page loading the main window will lose its focus.

After some debugging with Spy++ I've discovered that the Adobe Flash plug-in creates a WS_POPUP|WS_VISIBLE "Edit" class control with zero width and height. Since it is a visible popup window it gains focus and Firefox' main window lost its focus.

If I disable the flash plug-in then the problem goes away. You can also trigger the bug by using noscript and then click to view a flash object.

From my research the bug is strictly speaking not in Firefox, but since it happens *every time* I surf, on every Windows machine I've come across, I say this is a pretty annoying problem. Anyone know how to get Adobe to fix this? :)

Comment 10

[Kevin Brosnan]

Closing this bug as incomplete the user in Comment 9 is going to open a new bug.