Firefox 2 crashes when I try to play a flash movie or file (segmentation fault).:

On my system which is a Dell Optiplex GX 110 running Slackware 10 with kernel 2.4.26 and GCC 3.3.4 this happened a number of times. Here is a possible explanation:
When you install flash as the plugin you must follow the directions at the Firefox site , in addition to those at the Adobe flash site. The Flash player can be found here:
http://www.adobe.com/shockwave/download/download.cgi?P1_Prod_Version=ShockwaveFlash
It has an install script that does not put flashplayer.xpt in the proper place by default

here is a link to the answer to the problem:
http://plugindoc.mozdev.org/linux.html#Flash

Do exactly what they tell you there. Also you can type in the address window of your browser [ about:plugins ] . This will get you to a page with links to the above site (plugindoc.mozdev.org).
Before you start with the installation, be sure to find your mozilla directory, not the one in your home directory.
On mine it was in:    /usr/lib/mozilla-1.7/components
you will need to be root to copy flashplayer.xpt to that directory. This solved the problem for me. . . or so I thought. It still crashes occasionally. I ran the script that came with the flashplayer first. It did not copy the .xpt file to the correct directory by default. I needed to copy that file (flashplayer.xpt) to the components directory which is in the mozilla directory in:
/usr/lib.
This may or may not help in your particular situation.