So, some precision, in fact it's when you enable a screenlets in obtion menu: "allways on top", the full screen mode for a flash video, can't work on any site. I have several other screenlets "under" firefox on my Ubuntu desktop who are enable. And if I disable the screelets who is on top, the full screen mode work normally. In the exemple on the attachment file, I use "Netmonitor" on top Firefox and it's the "trouble". Hope this precision can help somebody.
So, some precision, in fact it's when you enable a screenlets in obtion menu: "allways on top", the full screen mode for a flash video, can't work on any site. I have several other screenlets "under" firefox on my Ubuntu desktop who are enable. And if I disable the screelets who is on top, the full screen mode work normally. In the exemple on the attachment file, I use "Netmonitor" on top Firefox and it's the "trouble". Hope this precision can help somebody.