427169 - firefox disappearing from task bar

Status: RESOLVED DUPLICATE of bug 246531

(Firefox :: General, defect)

Description

[Aaron]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.13) Gecko/20080311 Firefox/2.0.0.13 Creative ZENcast v2.00.14
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.13) Gecko/20080311 Firefox/2.0.0.13 Creative ZENcast v2.00.14

Lately I have had a strange bug with firefox that occassionally makes firefox disappear from the windows taskbar after switching to another program. 
This is a problem that happens several times a day for me, but not every time, and I don't know what the variables are that cause it. To get firefox to show up again I have to clear the desktop and then click on item on the taskbar one at a time until I find one that carries firefox with it when it opens. I don't know if this makes sense to you, but it is as if the tab for firefox slides up underneath the tab of another program and can only be exposed by clicking on that other program.

Reproducible: Sometimes

Steps to Reproduce:
I can't reproduce it. It seems to happen randomly.

Comment 1

[Richard]

  I too am suffering from this problem in Windows XP.

  I am using Firefox version 3.5.7 and, like Aaron, one of the Firefox windows present on the Start bar disappears when I switch to a different program. The window will come back after minimising/maximising other windows. I haven't tried alt-tabbing back to the missing window yet, so I can't confirm whether that works.

Comment 2

[Bill Skinner]

Same problem here in my recently installed Windows 7.  I am working with Firefox v3.6.

Does it have anything to do with moving my old profile to the newly installed 3.6?

Thanks.