When you click the "x" to close a tab in firefox there is a threshold you must wait before clicking the next "x" of a new tab will close the window. This is annoying and I want to set this threshold to zero. Is there a setting in about:config?
When I close a tab in FF 5.0.1 I can close the next tab immediately. I can close 4 tabs in a row (arbitrary number) with no hesitation at all.
Can you share what version of FF you are using? Is it possible that it may be related to computer performance, such as a slow processor? More information would be greatly helpful.
EDIT: One thing to try is to go to about:config and set 'browser.tabs.animate' to false. If that works, let us know. More info about this solution here.