It still doesn't works with youtube! Rated 2 out of 5 stars

"If the youtube videos take a long time to load, this is another problem"
Sorry mig but that can't be! I wrote it in my posting... if I disable the addon (and only this and no other addon) than all actions on youtube runs fine. And that is still my problem with downloadhelper since the versions after march or april in this year.

This review is for a previous version of the add-on (4.6.2). 

Re:

The Youtube HQ problem that occured on the 13th was fixed by 4.6.1 on the 14th. Another youtube change caused a similar issue on the 17th. Version 4.6.2 submitted on the 18th solves the problem.

If the youtube videos take a long time to load, this is another problem (described at http://bugzilla.downloadhelper.net/show_bug.cgi?id=5) and is due to a bug in your firewall.