Tab Problem?
when every time I minimize the whole window of the fire fox with lots of tabs, then open it up, the current tab always goes to the right of the last one, before it has no problem like this, the current tab always stay where it is when I minimize the window(like if the tab is the one at the third from the left, it will always be at the third from the left one).
Alla svar (1)
Try running Firefox in Diagnose Firefox issues using Troubleshoot Mode. If it functions properly in that configuration, then one of your add-ons is the culprit.