I had tweeted shortly after Firefox 3.5 was released that it was too unstable for day-to-day work use, and I had to rollback to version 3. Finally after successfully using Firefox 3.5 for about 3 weeks at home I thought I'd give it a go again and upgraded late last week. Today (Monday, 12-Oct-09), I've had two crashes. I suspect it is related to memory usage, as I've had many tabs opened and closed as I do some data cleanup in our CRM system.
Below is the last message upon restarting Firefox. While I'm disappointed and a bit frustrated, Firefox is embarrassed.
We'll see whether this is a consistent problem, forcing me back again, or if other daily tasks workout.