I had the same exact problem with and old hacked Linux distro. I went through every docs and forums over the Internet about Adobe Flash, uninstalled and reinstalled serveral times different browsers, but nothing really worked. It is actually still not doing it. I found it out when I installed another distribution (Debian) on the same hdd. It runs Iceweasel by default, so i just tried installing Flash and it worked just fine, never crashed. What happened was the old distro never detected the graphic card on my chipset, when Debian did ok. You need to have the right driver for your graphics, or it will hardly work... Just take a look at it. Good luck.