I have been facing some problem with Flash in Firefox 2.0 in Ubuntu 6.10 (Edgy). Whenever you get to visit a page that has flash embedded in it, Firefox crashed. It was getting very annoying though.
To solve the problem, all you have to do is change the ColorDepth of the Default Screen to 24.
To do so, you can do the following;
Start the terminal and type
sudo gedit /etc/X11/xorg.conf
Then, look at the screen section for default depth and change it to 24, where it’s the highest depth. It should look something like this.
Identifier "Default Screen"
Device "NVIDIA Corporation NV18GL [Quadro4 NVS AGP 8x]"
Monitor "Generic Monitor"
Cheers, goodluck and Enjoy.