Could be, but Project Red is within the 1.0.3 of Monster.
But is it Biomes of Plenty that is somehow blocking it out?
I also read this:
Could that be it?
http://ftbwiki.org/GeoStrata
Just checked the Project Red config for Monster, and volcanoes are not set to generate (along with Marble caves). So you can change that in the config if that's an option for you.