You were the first to Vote to close the question. You'd left an explicit comment:
"Voted to close. This is no longer really an issue in current versions of Firefox".
The most recent comment was:
You also didn't mention which version of Firefox, so this question is useless now.
Considering you had voted to close & it was a year old and nowit's no longer an issue, I didn't see any reason why it should be around and deleted it.
If you're curious, here's the full question.