Rated 4 out of 5 stars

Great add-on but I too am having problems with it since Firefox 19 came out. I hope you will have a fix for it soon.

This review is for a previous version of the add-on (4.9.13). 

Can you give a try with this beta version http://www.downloadhelper.net/install-beta.php?version=4.9.14b1 and report if it fixes the problem in the bugzilla interface http://bugzilla.downloadhelper.net:8080/show_bug.cgi?id=496
Thanks.