Now, I’m not sure if this is a problem on my side, or an incompatibility of the extension with Firefox Aurora, and other Firefox development builds. Cannot test it. What I can do is to post an alternative for users who are experiencing the same issues with Download Helper.

I tried several download add-ons for Firefox and found the extension Flash Video Downloader to be working on many sites. The extension does not come with a build-in sitelist that you can use to find new video sites. The core downloading functionality on the other hand is similar.

The extension indicates downloadable media on a website with a change of the add-on icon that is located in the status bar of the browser by default.

A click on the button opens the download window where the video to download can be selected. Handy if multiple videos are located on a page.

A download button is placed next to each video in the download window. You can click it to send the video download to the Firefox download manager. The very same page offers to download all listed videos which sends all of them to the download manager instead.

There is a popup at the top which can be used to switch to previously accessed pages and the videos that they contained to download those as well.

The convert this video button leads to the company website that is offering a free video converter for download. A click on the status bar button on some sites redirects the user to a website where the videos can be downloaded. This is for instance the case on Gametrailers.

A right-click on the program icon opens a menu with links to tools and settings. Settings are used to make interface changes, for instance to define where the button appears in Firefox. You can also configure the download folder here and the hotkey.

Flash Video Downloader works on many popular sites. I have tested a good dozen of them including YouTube, Gametrailers and Facebook. Firefox users can download and install Flash Video Downloader from the official Mozilla Add-On repository.

Download Helper is a new Opera extension that improves the downloading of files from specific file hosting sites. The Opera extension supports several popular file hosting services including Hotfile, Megaupload, Depositfiles, 4Shared and Mediafire.

Here are the effects on the file hosting sites:

• On Megaupload.com it will automatically start download after the time ends.
• On Hotfile.com it will popup window where you can type captcha and download link will appear without waiting.
• On Depositfiles.com it will automatically choose Free download and automatically start download without
  waiting 60 seconds to download file.
• On 4Shared.com it will automatically start download after the time ends.
• On Mediafire.com it will automatically start download.

The extension will start to download the selected file automatically once the wait time is over on three of the five file hosts. It can bypass the wait time on Hotfile and Depositfiles making it an interesting extension for users who download files from Hotfile or Depositfiles regularly.

Download Helper supports additional Georgian file hosts as well allowing the user to download files instantly from all supported file hosts.

Opera users who use at least one of the supported file hosts on a regular basis might want to test the Download Helper Opera add-on. Please take note that add-ons only work in Opera 11 and later.

Icon ? Yes you may add an download helper icon to your toolbar, use it from the tools menu or from the context menu. I would prefer an entry to the statusbar instead of an toolbar but I can live with it for now. The icon plays a short animation once it detected a file that can be downloaded. Clicking in the icon displays a list of all files available and moving the mouse over an entry marks the file on the webpage that would be downloaded.

One very nice feature is to mark part of the website and use the context menu to view a list of all files that can be downloaded from the marked area. Right-clicking one link is of course available as well.

Download Helper currently supports not that many different websites as video downloader but you could try the “check url” option to see if you can download a file although it is not displayed in the list of auto-detected files.