582401 - Unable to go to a web site when opening a new tab in Firefox 4b2

Status: RESOLVED INVALID

(Firefox :: General, defect)

Description

[Frank Geurts]

User-Agent:       Mozilla/5.0 (Windows; Windows NT 6.1; WOW64; rv:2.0b2) Gecko/20100720 Firefox/4.0b2
Build Identifier: Mozilla/5.0 (Windows; Windows NT 6.1; WOW64; rv:2.0b2) Gecko/20100720 Firefox/4.0b2

I have the same (or similar) error with with Firefox 4b2.  On startup a dialog
box pops up with the message TypeError: Components.classes[cid]is undefined. 
When I click OK the startup completes, and any previously opened tabs are
displayed. However if I open a new tab and select a website from the drop down
history list or type in the name of a web site I want to go to and press enter
nothing happens.  Beta 2 is currently unusable for me in this state.

Reproducible: Always

Steps to Reproduce:
1.  Start Firefox 4b2 after upgrading to it from 4b1
2.
3.
Actual Results:  
Cannot go to another web site by opening a new tab

Expected Results:  
connect to the selected website when pressing enter

Comment 1

[Matthias Versen [:Matti]]

Please try http://support.mozilla.com/en-US/kb/Safe+Mode

Comment 2

[Frank Geurts]

Works OK in safe mode ie when a site is selected form the drop down list Firefox immediately loads it or when a site name is entered in the address bar and enter pressed it loads

Comment 3

[Matthias Versen [:Matti]]

In that case the problem is caused by an installed extension.
Disable them one by one to find the extension that is doing that.

invalid because it's not a Firefox bug

Comment 4

[Frank Geurts]

AVG Safe Search 9.0.0.845 disabled and problem no longer occurs.