I posted a message on Bugzilla. I don't know what the process is for filing an official grievance. I don't expect a problem to be solved for someone using an old comptuer and an old version of Firefox.
From what I've read online, and tried myself, it has something to with Firefox, certain web sites, webGL, and the graphics driver in the Radeon X1600. I thought heat might be a factor, but I guess not. Even if I disable webGL and hardware acceleration, I stll get kernel panics.
The solution is for certain sites to use Opera or Safari.
