How can I get Firefox to leave the mouseover preview on until I move the mouse away?

Factual Questions
1

First, I’ll admit I did a minimal search on Google and Firefox’s help files. Minimal, but apparently not thorough.

On an SD forum page, I like holding my mouse over a thread title to get the preview window that shows the first paragraph of the article. I like it so I know whether or not I want to click to read the entire thread.

But it goes away after five seconds. (Measured in alligators.)

Is there a way to set it so that the preview box stays there as long as I hold my mouse over the thread title?

2

A quick google gave me this: https://addons.mozilla.org/en-US/firefox/addon/11233

However, I don’t know if there are ways (such as a key in about:config) that don’t require an extension.

3

THANK YOU!!!

Part of problem is I didn’t know exactly what I was searching for, and the other problem is I didn’t realize it was only fixable with an add-on. Which seems odd.

Again, thank you.