Thanks everyone.
For the record, I've gotten MATHLIB to work in C++ by creating the C wrapper functions based on Arch's guidance. I'm not sure if this will slow down my code any, since it's just a function call inside a function call, and now that I've figured out this method I can add new MATHLIB function calls to my program with ease in a matter of minutes.
Travis: Since my code now works this way, I haven't tried your pragma correction. If I do, I'll surely post back with feedback.