I made Opera 7.11 Build 2880 Windows 2000 Sun Java Runtime Environment version 1.4 (1.4.1_03) more stable by limiting preferences-->network-->max connections to server to 4, max total connections to 8, preferences-->history and cache-->typed in addresses to 50, visited addressed to 100, memory cache to 4MB, disk cache to 2MB, and removing all my languages from preferences-->languages-->preferred languages for Web pages.
I identify as MSIE6.0. I didn't change that.
Two days now, and Opera has not crashed.
Opera has crashed since then. And often.
Please let me know if you know how to stop Opera crashing.
Version 7.23 seems good. For about two months now, it has crashed maybe once every two weeks.