The newer versions of Real Player have added an annoying feature which will allow you to download a video playing in the browser. At first I thought disabling all the RealPlayer plugins within Firefox would take care of this. It did not and then I noticed the same thing happening in Chrome. After some poking around in RealPlayer (which I rarely use) I found out how to turn off this feature.

1. Launch RealPlayer*
2. From the RealPlayer drop-down menu at the upper left select Preferences..
3. Click the Download & Recording category (2nd from the bottom)
4. You can either un-check the enable box (will turn off for all installed browsers) or in the section below select on of the other options.
5. Click OK
6. Close and restart Firefox

* You can also click the drop-down button on the right-side of the button and this will open RealPlayer preferences to the Download & Recording category. However, accessing this method may cause your system to become unresponsive for a few seconds.