Help, I think I confused my Catasetum!

[Lady Oscar]

I picked up this little Monnierara Millenium Magic 'Witchcraft' at the Honolulu Orchid Society show last October. When it started to get "cold" in November/December I let it dry out well between waterings (watering about once a week), but it showed no sign of wanting to drop its leaves, and a couple weeks ago it started growing a new shoot.

Then, a couple days ago, all three leaves on the main pseudobulb turned yellow, and yesterday they dropped off.

If I stop watering, I assume the new growth will be sad, but if I keep up the watering, I'll rot the roots of the dormant bulb. What should I do? ^^;