576379 - Navigating to a website starts a new instance of firefox

Status: RESOLVED DUPLICATE of bug 557225

(Firefox :: General, defect)

Description

[Kaustubh]

User-Agent:       Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_4; en-US) AppleWebKit/533.4 (KHTML, like Gecko) Chrome/5.0.375.70 Safari/533.4
Build Identifier: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:2.0b1) Gecko/20100628 Firefox/4.0b1

With firefox 4.0b1 on OS X 10.6.4, when navigating to a new website (new address in the address bar), a new instance of firefox is started.

Reproducible: Always

Steps to Reproduce:
1. Start firefox.
2. Enter a new address in the address bar.
3.
Actual Results:  
A new instance of firefox is initiated, and a new firefox icon appears in the dock. Clicking on this icon does not show a new firefox window, and the OS X menu bar has only a "Firefox" option available. Clicking on this option does nothing. If this firefox instance is killed, every time a new address in entered in the address bar a new instance is initiated. 

Expected Results:  
The additional instance should not be started.

Comment 1

[Kaustubh]

This seems to happen only when I visit sites that require a plugin. Killing the new instance causes firefox's plugin crash handler to display a "this plugin has crashed" message.

Comment 2

[Tony Bajan]

This is bug 557225

Comment 3

[Tyler Downer [He/Him]]

This bug was reported using a pre-release version of Firefox 4. Now that Firefox 4.0.1 final has been released, can you please update and retest your bug? A fresh profile would be a good starting place to test, 
http://support.mozilla.com/kb/Managing+profiles. If you continue to see the issue, can you please update this bug with your results?

Filter: firefox4prebugsunco