That could be your experience with Firefox, but the difference between Firefox 1.0PR and 0.9.x is primarly that 1.0PR has more bugs fixed. (I personally found them both to be stable, I suspect in your case its Firefox balking on using a configuration created from an earlier version because I've had this problem, but thats neither here nor there.)
I guess there's two uses for the word stable. Stable as in unchanging. Stable as in less likely for a program to crash. The former doesn't mean you release a distro with old software, it means you release a distro and maintain it (security updates) for several years, perhaps with a longer update cycle. And its the former that enterprises want. And as I already stated a program being older doesn't magically mean its going to crash less, certainly when talking about minor revisions (like the difference between 0.7 and 1.0 of Gaim) newer is better.