I have this same problem. Firefox 4 on 10.6.7 on a 2009 unibody Macbook Pro.

I've noticed that I only have the problem when I'm using multiple monitors and my Firefox 4 window is to the left of the Mac OS X Menu Bar.

My typical arrangement is: laptop monitor with firefox 4 window TO THE LEFT OF external Dell 24 inch monitor with Mac OS X Menu bar.

Moving my Firefox 4 window to the external monitor allows me to open a window.

How do you make firefox 4 compatible with snow leopard. Or alternatively how do we enable snow leopard to use firefox 3.6?

I've got an abonormal amount of users with the similar issues. All are on latest 10.6.7 and either can't open new tab's or windows. For those users with issues not being able to open tabs upgrading to firefox4 fixed the tab issue; but those users were met with new issues by not being able to open new browser windows post update..

Wow - that is weird. I'm also using an external monitor (mac cinema display - 24"?), with my laptop to the left, and you are correct - I can't open a new firefox window if the 1st firefox window is on the laptop display, but it works if ff is in the external display. I have osx set to use the external as the main interface (all the menus are on the external). Sounds like a bug.

Still running osx 10.6.7

Similar problem for me. I'm running firefox 4 on OS X 10.6.7 Mac Pro with 2 video cards, 3 monitors. The main video card has 2 monitors, both of which allow me to open in 'new window' without any problems. My third monitor is connected to the second video card, but firefox's open in 'new window' does not work on this monitor. Dragging a tab out of the browser also makes the tab disappear.

I've also noticed that although the window won't open AT THAT TIME, it appears to cache the request somewhere, and under the right circumstances when restarted ff I'll get the dozens of new windows that I'd previously unsuccessfully initiated.

I attempted to search the 'bugzilla' database - and open a new bug report if I couldn't find an existing one for this issue, but apparently they are doing upgrades on the site, and the search just hangs. I'll try again later.

ch

I am have same problem as well. Using a MBP mid-2009 with a 24" LED ACD. Can open tabs but cannot open new windows. The "Command-N" appears to be registering (the "File" menu briefly lights up) but, alas, no new window. Sure hope this is fixed sometime soon!

I've had this problem with very similar setups to those above. When running dual monitors I cannot :

• Open new window using menu or shortcut keys
• Open new tab and drag it out of the current window which normally would move it to a new window

A bit of playing around and I have found that this is a glitch for dual displays... If you move the browser window to your primary monitor - i.e. the one with the dock and top info bar - it works.

the windows open - they're just invisible. or actually, probably off-screen somewhere in the ether.

HOW FREAKIN ANNOYING.

After reading responses here and realizing I too run a multi monitor setup on a MBP that has the mac bar on the external screen, I realized that this problem is only occurring while FF is on my MBP and not on the external screen. after further testing (I moved the mac bar back to the MBP) I can open new windows from either screen without problem

Good to know I'm not going crazy! Been having this same exact problem.

I have a Feb 2011 MBP 15", 2GHz Core i7 w/ 8GB & high res screen. Running the built in screen plus one external monitor connected to the DVI port on the monitor via a BookEndz port replicator. Using built in video card only. Monitors are not setup to mirror, and external monitor is the primary. Firefox version is 4.0.1

• Cannot open any window (including viewing source and page info) when both monitors are running.
• The new windows, however, will show under "Window" in the menubar.
• Selecting one of the missing windows does nothing (the check in the Window menubar does not even move to the window I selected, but will stay on the first one).
• If I quit Firefox and restart (windows are set to repopulate on restart), the new Windows I'd opened in the previous session will now appear (sort of). They appear as tiny vertical slivers (appears to be 1-2 pixel(s) wide not including shadow). I can select these slivers to bring them into focus and close them (Cmd-W).

I can provide additional info and screenshots if it helps troubleshoot.

I have the same problem, but I am running on an iMac, Mac OSX 10.5.8 with FF 4.0.1.

If my FF window is on the main monitor, I can open new windows successfully. However, if my FF window is on the 2nd monitor, whenever I CMD+N (or open a new window from the menu), the window "opens" but isn't really there.

In other words, I can see the window listed under the FF Window menu, but I can't see it, and I can't manage to give it focus. I tried CMD+~ to cycle through the FF windows, but I could never give any window "opened" from the 2nd monitor focus.

As someone else stated, it's like they're in limbo somewhere.

this is incredible but my boss thought maybe it had something to do with the alignment of the monitors. On a mac I went to system preferences > displays > arrangement. I then top aligned my monitors (they were bottom aligned). My issue is fixed. Hope it works for you too!

I can confirm the observation of claLeah. Aligning the 2nd screen on top works for me too. But i's still a pain in the A..

Had this too, I can confirm claLeah's solution two posts up fixes this. Thanks!

I have this problem too, aligning the monitor on top does indeed fix the problem but this is not a solution since this offsets my monitor from what they actually are. Any chance this probem will be fixed eventually?

Also noticed that the Firefox window must be a little more than 50 % into the main monitor for the problem to go away, anything below that and the new window goes nowhere.

Chiming in with a "me too" response. I'm a coder, and my web screen is my "other" screen; my main window is just a series of shells and tabs of shells. Firefox runs on the second monitor, the one that isn't directly in front of me; if I put Firefox in the main window, it works fine (can make new windows, can see download windows, etc). If I put it in the second screen and have the screens aligned any way other than top-aligned, I can't open new windows. Downloads still complete, I just don't *see* them. Since the second screen is smaller and shorter, I don't want it top-aligned; with it top-aligned, dragging from one screen to another makes the image drop about 4 inches...which looks about as bad as it sounds.

Cross-posted

I've had the same problem but I have a work around for it.

1. Do you use dual monitors? 2. Is Firefox displayed on the secondary monitor?

My solution:

1. Move the visible Firefox windows to the primary monitor. 2. Close Firefox completely. 3. Open Firefox.

As long as you keep Firefox on the primary monitor, you should be able to open new windows and drag tabs to create new windows as much as you want.

P.S. Any devs reading this, please fix!! Its really annoying.

OMG claleah Thx

claLeah

HOLY COW - Thank you so much for a 'fix' albeit one that isn't really ideal for my dual monitor setup when dragging between apps... I like the bottom justified personally. BUT OMG what a great day! Thought I was going insane (ER).

TJ