Users of the Firefox browser might have gotten a surprise today when they fired up their PCs.

Mountain View, Calif.-based Mozilla Corp. – the makers of Firefox – released the latest version of their popular and free (think the two are related?) Web browsing software yesterday, pushing out updates to existing users.

Firefox 1.5.0.4 is more stable, the company says, and also fixes several important security vulnerabilities. More info at www.mozilla.com.