User Agent: Mozilla/5.0 (Windows NT 6.2; WOW64; rv:17.0) Gecko/17.0 Firefox/17.0 Build ID: 20121008042009 Steps to reproduce: Suppose I am write something wrong and check them by right click. if I go to another tab then it's still exist. Actual results: http://postimage.org/image/mrklwdbf5/ Expected results: I still have this problem on every tab. Can firefox stop showing me this thing.
Have you tried unchecking the "Tools/Options/Advanced/Check my spelling as I type" option ?
Please try what Paul suggested in comment 1.