Every time I watch a youtube video it resets back to 50% and blasts my ears. 

The previews versions had one or two instances within Windows sound mixer. The new version has 5-7 instances and I have my sound on 50% while firefox is set to 20%. Every time I watch a youtube video it resets back to 50% and blasts my ears. Every time I adjust the sound back to 20% it just resets back to 50%. Picture one - "firefox1" is showing two instances of firefox where I have a video open. Picture two - "firefox2" is showing me opening two youtube videos and both are at max volume. Becoming really annoying and would like some help. Never had such problems before!