Are you having a lot of frozen apps? If so, it sounds like you may have some software conflicts. Check your applications and make sure you have all the updates needed to play nice with 9.2.2. Any particular combination that causes this to happen?
As far as the Com+Op+esc, if the application itself is the cause of the freeze then you should be able to get out of it with the system still running. But if the freeze is caused by an interaction with another program or the OS itself, then a total lockup is not that unusual. When I run IE, Eudora, Sherlock (and sometimes others) and go online, it is a rare evening that a lockup doesn't happen and a restart required. They all just don't run smoothly when online together. Even when you have to force quit and the OS (finder) stays running, you are on thin ice as to when the OS will go down eventually.
That's one of the reasons X was developed. Though I have had to restart a few times even in X when Classic apps are force quit or X apps barf .