Why is Dark Souls showing double health bars on bosses?

When I fight bosses I see 2 health bars (for each boss) along the bottom. One is yellow and uses most of the bottom of the screen, the other is red and is below the yellow one and in the left quarter of the screen. It is about 1/4 the size of the yellow bar.I have DSFix installed. Is this an issue with that? Any ideas how to fix so that only one bar displays?Screen shot from http://www.neogaf.com/forum/showthread.php?t=488240&page=119