Having successfully upgraded to sid, I'm in the process of trying a
firefox-3.6.8 build from the mozilla source tree (modulo the usual small
patches for alpha). I was pleased to find that a 3.5.3 build I made
before my primary hard disk died works with an up-to-date sid: symbol
reference errors kept it from working under lenny.
Once I've got some confidence that the tool chain is reasonably robust,
I'll revisit the KDE4 debugging I was attempting to do several months
ago. The developers have been more patient with me than *I* would have