Uninstall Zonealarm. It's a pretty foul piece of software once it breaks down - unfortunately very few people realise it until it happens to them. I'm not sure if reinstalling fixes it, since it doesn't actually clean itself from the computer properly when it uninstalls, but it's better for it to not be running once it's screwed up.

As for the "underscore" thing, maybe play around with power management, and test enabling/disabling it in the BIOS or something.