Cannot open more than one window with Firefox

Question

I've been having this problem for a couple of weeks, now, and I've run out of ways to try and fix this.
One day, after starting my computer up, I opened Firefox. No big deal, everything looks fine, tabs are working, etc. Then, when I went to open a second window, nothing. The first window still works fine, I can open tab upon tab, but it just won't open any more windows.
As much as I'm a fan of the browser tabs, I still prefer to have them spread out over more than one window.
I've read through a ton of different troubleshooting walkthroughs and whatnot, reinstalled three or four times, restored settings, but nothing works.
Well, not entirely, I guess. Here's the part that I can't quite figure out. When I disable every single addon, Firefox works just fine. I've done the checking down the list, trying to single one out, but it's *any* addon. Even something as simple as a dictionary search ([https://addons.mozilla.org/en-US/firefox/addon/68/]) causes this to happen.
I've checked with an older computer with an older version of Firefox, and it still seems to work fine with addons enabled, so I'm wondering if this is an update issue?
Would reverting back to a previous version of Firefox solve this, and if so, where would I be able to find downloads for a previous version?
So, like I said, I'm at a bit of a loss here. Sort of at a crossroads for trying to figure out what to try next, so I'm hoping someone a bit more knowledgeable can help steer me in a direction.
Edit: I just noticed that the posting includes system information with my question. I should clarify that I'm posting this from an older computer with an older version of Firefox. On the computer that I'm having this issue with, I'm using the newest version of Firefox (3.6.8).

Answer 1

Some old posts indicate the following add-ons have caused the problem of not being able to open a new window in Firefox in the past. If you have any of them you might want to disable or uninstall them to see if that is causing your problem.<br />
* HP Smart Web Printing Toolbar
** https://support.mozilla.com/tiki-view_forum_thread.php?locale=en-US&comments_parentId=531462&forumId=1
* Skype
** https://support.mozilla.com/tiki-view_forum_thread.php?locale=en-US&comments_parentId=472881&forumId=1
** https://support.mozilla.com/tiki-view_forum_thread.php?locale=en-US&comments_parentId=531462&forumId=1
* Zone Alarm Toolbar
** https://support.mozilla.com/tiki-view_forum_thread.php?locale=en-US&comments_parentId=472881&forumId=1
** https://support.mozilla.com/tiki-view_forum_thread.php?locale=en-US&comments_parentId=624545&forumId=1
** http://forums.zonelabs.com/showthread.php?t=73592&highlight=firefox+window
<br />
You need to update your plug-ins. It is important to keep them updated due to continuing security fixes and improvements in those plug-ins:
* Adobe Shockwave for Director Netscape plug-in, version 11.5 (you '''<u>may</u>''' need to update)
* Shockwave Flash 10.0 r32
* Java Plug-in 1.6.0_11 for Netscape Navigator (DLL Helper)
#Check your plugin versions: http://www.mozilla.com/en-US/plugincheck/
#*'''Note: plugin check page does not have information on all plugin versions'''
#'''Update Shockwave for Director'''
#*NOTE: this is not the same as Shockwave Flash; this installs the Shockwave Player.
#*Use Firefox to download and SAVE the installer to your hard drive from the link in the article below (Desktop is a good place so you can find it).
#*When the download is complete, exit Firefox (File > Exit)
#*locate and double-click in the installer you just downloaded, let the install complete.
#*Restart Firefox and check your plugins again.
#*'''<u>Download link and more information</u>''': http://support.mozilla.com/en-US/kb/Using+the+Shockwave+plugin+with+Firefox
#'''Update Shockwave Flash'''
#*Use Firefox to Download and SAVE to your hard drive from the link in article below
#*SAVE to your Desktop so you can find it
#*After download completes, close Firefox
#*Click on the file you just downloaded and install
#**Note: Vista and Win7 users may need to right-click the installer downloaded and choose "Run as Administrator"
#**Note: Most browsers other than IE will also get updated with this one download
#**Note: To update IE, same procedure '''<u>but use IE</u>''' to go: http://fpdownload.macromedia.com/get/flashplayer/current/install_flash_player_ax.exe
#*After installation, restart Firefox and check your version again.
#*'''<u>Download link and other information</u>''': https://support.mozilla.com/en-US/kb/Managing+the+Flash+plugin#Updating_Flash
#'''Update Java:'''
#* Download and update instructions: https://support.mozilla.com/en-US/kb/Using+the+Java+plugin+with+Firefox
#* Removing old versions: http://www.java.com/en/download
<br />
You are using an out-of-date version of Firefox. Unless you have a reason for using that old version, you might want to consider upgrading.
*The Firefox version series 3.0.x is no longer being supported or updated, even for security issues.
*The last version in the 3.0.x series was 3.0.19 which was released 03/15/2010.
*You are using version 3.0.13 which was released 07/31/2009.
Consider upgrading to the current version, Firefox 3.6.8. Firefox 3.6.9 is scheduled to be released in a few days and the new Firefox 4 will be released later this year or early next year.
* See: https://support.mozilla.com/en-US/kb/Upgrading+to+Firefox+3.6
* Or you can download the full installer and save it to your hard drive for installation from: http://www.mozilla.com/en-US/firefox/all.html
* Also see: http://support.mozilla.com/en-US/kb/Installing+Firefox