The normal behaviour is to open the add-ons manager in a tab. You should check to see that an add-on is causing this to happen. For details of how to do that see troubleshooting extensions and themes.

One add-on that can cause this is Mr Tech Toolkit.

Thank You, it was the problem. Now just have to wait until they update Mr Tech Toolkit :)

A workaround for you if you wat to keep Mr tech Toolkit. If you create a bookmark and set it to about:addons you can use that to open the add-ons manager in a tab.

As you are probably aware, much of the functionality of Mr Tech Toolkit does not work in Firefox 4 beta.

Thanks again, it was helpfull.:) Tell me please if You know, in Firefox 4 will we be able to install extensions without restart?

There have been a complete overhaul of the add-ons system for Firefox 4. A part of the change is allowing add-ons to be installed without a restart, but this only works for add-ons that have been written to take advantage of this new option. Most current add-ons will require a restart.

how can I get it to be back to the small popup window for the add-on. prefrence even thou I still aviod it because i still love the old style and SeaMonkey still has that whew. But those are nice and small and clean and easy to use and aren't big and bulky like the new add-on manager. But how can I get the popup dialog . anything in about::config I can hack ? I'd love to see the option for the classic views its a much better option and more fair to people. I also hate the fact when I click the add-on it auto move me to that tab. I have that turned of with middle click. would be nice if it was a middle click option . But even then I'd hope it does auto take me there. Hot mail too thats what the middle click is for to open another tab if you want but as I said witht he option to go to it then and there ot when you want to. Seamonkey 2.1a3 it still works right so I dunno what wrong with firefox . thats all the same things like ie :( . I don't like annoying popups but a config small popup is fine thanks

It's a tab so you can use the tear off tab feature to move that tab to a new window by dragging that tab slightly down into the browser window and release the mouse. Then you can resize that window as you like.

well detach I know about but thats not what i want . I want it to be like it was. open in the smaller cleaner popup like it used to(in preference the choice between the newer bulky one or the older simpler one). Plus the auto switching to tabs when you have it turned off is horrible. I see from preference it opens a new window which is still as bulky too.