Subject: Re: [Mozilla Hacks - the Web developer blog] New Comment On: Firebug 1.10 New Features
I have experienced something similar and as soon as I have time I will attempt to create a minimal test-case for posting the bug I have experienced. I am not certain that it is precisely the same as what you are experiencing, but on the surface it demonstrates many of the same characteristics you describe.
However, in the meantime, I have found a workaround which may also be applicable also in your case.
When I have experienced the inability to set breakpoints, I have also experienced the inability to use the "script-selection" tab, just below the main menu. This occurs when the main-menu "Script" tag is selected or attempted to be selected. See attachment (FirebugOutToLunch.png).
Fortunately, when this occurs, the "Console" tab is still workable. You can work around the problem with the following method:
1. In the module you want to breakpoint, use console.debug() to place a log message into the console.
2. When you gain control in Firebug, select the "Console" tab and then use the log entry that you have created to navigate to the module of interest -- in the example attached, you would navigate by selecting "qTreeDisplay.js (line 402).
3. Firebug then transitions you, by default selecting the "Script" tab, with the "script-selection" drop down, pre-selected to the javascript module of interest.
I have been able to work around the problem you described with this method.