Several times when I need to use a font that's not in the combustion* text tool presently, I've had trouble getting the new font to show up. Photoshop recognizes the font just fine, but not combustion*. I'm working on Mac, using Master Juggler to activate fonts, and really need to animate the fonts in combustion*, not just import static Photoshop files.
Did you try to load the font into your system fonts? I think if you do this when you go to use fonts in C* your font should be in the list of fonts on combustion. I am pretty familiar with macs and I think that will do the trick--unless of course you dont want to do that. I had a similar problem on my PC so I just put the font into the system fonts folder and BLAM, instant fonts in C*.