User Agent: Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/20100101 Firefox/17.0 Build ID: 20121128204232 Steps to reproduce: I think it is nearly the same bug 251993. By writing an email : I type : "probllème" and I delete one "l" immediately after typing it. Actual results: The result is in the attached file. The word "problème is half underlined. Expected results: The word "problème" should not be underlined because it is correct.

Petit, thanks for reporting. I think we have that bug on record already. For ease of tracking and analysis, adding relevant bugs. Can you try this: a) On your testcase composition of attachment 690440 [details], after the error occurs: b) Click in msg body, then Ctrl+A to select all of msg body c) From main menu, Insert > HTML d) verify if there are too many <font size="xx"> tags in the source which you did not add yourself, and let us know Alternatively, press Ctrl+Shift+Enter on your composition after error is seen, then go to local folders > outbox, select outgoing msg, Ctrl+U to see source, copy or save into text file, attach source to this bug ("add an attachment")

Window after Insert > HTML in my testcase.

Thanks Petit, your attachment 695740 [details] shows this to be a duplicate of bug 812638 where this issue will be fixed.