The plant was labeled/sold as Zygopetalum jugosum from Alvim Seidel Orquidario Catarinense, in 2005. The lip measures 2.0 cm long, 1.5 cm at the widest. I don't know what I have!
I also have a Zygopetalum pabstii purchased in 2006. I expect it to flower in the next cycle.
Is the picture above a Z. pabstii? There is no chance that I switched labels.