firefoxreboot
In the Add-ons window, if I enable/disable an Extension, a yellow bar with a "Restart Firefox" button appears. This tells me "Firefox will try to restore your tabs and Windows when it restarts."
I want it to pick up some new plugins, and not enable/disable any existing ones. How do I restart Firefox manually, without losing my tabs/Windows?
Problem was in newest ATI graphic card driver.
If anyone else gets this problem after updating their graphic card driver this is how to fix it:
For Windows XP:
That will rollback your graphic card driver to previous version and fix the above mentioned problem with Firefox.
EDIT: Seems to be somewhat fixed with the latest drivers. Still happens on occasion but rarely. If however you disable hardware acceleration in firefox and then restart the browser it will be fixed completely.
For that, there once was an addon called "Open Chromeless" – but it was removed from AMO. A work-around is described here; I've just checked it and it seems to work. Partly. Cannot get rid of the addressbar, and there's a frame around the window. If you can live with that:
In the editor, enter
window.open("https://superuser.com/", "_blank","width=800,height=600,resizable");
(replace the URL with the one you want to use)
Now a new "chrome-less" window should open with the page specified. Resize it to your needs:
Screenshot of the "chromeless window" (click to enlarge)
Right-click next to the addressbar, as shown in the screenshot, lets you disable the address bar as well (untick "Navigation toolbar") – but note that would remove it from your main window as well.
I'm aware this does not fully match your request (it's not launching from the command line, and leaves at least a frame around the window), but it comes as close as I could get to it.
Best Answer
Go to Edit > Preferences > Main > When FireFox starts and select Show my windows and tabs from last time. Once. After that, you can close FireFox, and it'll be remember everything you have open to show you next time you start it
[edit] For Firefox 5 on Windows, the option is located at: Tools > Options > General > When Firefox starts: Select "Show my windows and tabs from last time"