Help me, geek folks!

More and more frequently, I'm getting these crashes. I'm running Ubuntu (8.04, hardy heron, will upgrade to the next version soon, Gnome 2.22.3). When the thing switches to a blank screen, it then quickly replaces the blank screen with this:

Starting anac(h)ronistic cron anacron [OK]
Starting deferred execution scheduler atd [OK]
Starting periodic command scheduler crond [OK]
Starting web server apached [OK]
apache2: could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for server name [OK]
Checking battery state... [OK]
Running local boot scripts (/etc/rc.local) [OK]

And then it hangs up there, and the only way for me to make anything happen is to power down the computer and restart.

What's goin' on?