Youtube error

YouTube's HTML5 player failed to play on Mozilla SeaMonkey browser.
To make it work do the following:

1. Go to the about:config page
2. Set the value of media.fragmented-mp4.enabled to false

UPD: that settings prevents some site to show video gifs.
Looks like this setting works better:
media.mediasource.webm.enabled: true

SeaMonkey 2

Google docs site stopped working with old version (1.x) of SeaMonkey browser, but newer version (2.x) is not compatible with the theme pack I made. The default one looks ugly. So I postponed the upgrade.
But recently I found out there is quite pretty theme for the new SeaMonkey available.
So, now I'm with 2.0
One major difference is discovered - it does not keep a process in the memory anymore, loading each time fresh. It loads pretty fast, though.
Another problem - they have reversed the mouse wheel direction and have not provided any option. What a stupid decision! I scroll the wheel toward myself because I want see the page context closely, but in this version the content becomes smaller. Another case when stupid majority overruled a common sense.

Upd: In this case I was stupid. I've found how to change the direction and it's exactly how it was suggested. The only difference, I should do it using the UI dialog, not by the about:config preferences.
So, to reverse the zoom direction need to uncheck the "Use system default" checkbox and enter the "-1" value to the "Scroll the document by" input field. That's it.