Never had this problem before, recently when I am on Ebay page and if the item is using shipping cost calculator to show shipping cost it doesn't work, regularly it shows the calculated shipping cost automatically when I am already logged on the site and it figures it out by my zip code but now asking me my zip code and after I enter it keep asking my zip code again doing the same thing and can not calculate the shipping cost. When I open the same page with MS Internet Explorer it automatically calculates my shipping cost without entering my zip code. Firefox worked fine until recently never had this problem before. I am not sure what is causing the problem, could be an add on, Just before submitting this report I restarted Firefox in safe mode without the add ons still it doesn't work automatically but this time when I enter the zip code and pres calculate button it shows the calculated shipping cost. I am guessing this problem arose after one of the recent Firefox upgrades. Hoping you have a fix for this problem and let me know the solution Thank you