I tried to using Firefox/3.6 (.NET CLR 3.5.30729) (tete009 SSE2 PGO) recently. I just found that when I saw the YouTube website, firefox can't show the flash movie correctly.
I'd check my flash player version
Shockwave Flash 10.0 r45
application/x-shockwave-flash Adobe Flash movie swf => Yes
application/futuresplash FutureSplash movie spl => Yes
It looks like the installation is successful.
Then I checked your suggestion
"I recommend changing the value of "general.useragent.extra.firefox" from "Minefield/…" or "BonEcho/…" to "Firefox/…", and some sites and add-ons will work properly."
But the value of "general.useragent.extra.firefox" is "Namoroka/3.6", neither "Minefield/…" nor "BonEcho/…".
I tried to change from "Namoroka/3.6" to "Firefox/3.6" and it's still not worked.
So, I tried the last way => Message to you
My system information is :
OS : WinXP Profession SP3
CPU : Intel Core(TM)2 Duo E7400 @ 2.8GHz
RAM : 2.0GB
I hope these information are enough for you, thanks a lot.