curling leaves on Prosthechea cochleata

[Sylorna]

I got a very very very healthy prosthechea cochleata in bloom at an orchid show, about 2 weeks ago. It continues to bloom well (although I did loose one bud).
I have noticed the last 2 days that it's leaves, which were originally flat are now starting to curl under on the long edges and I'm not sure why this would happen.

Conditions:
Good indirect sunlight (sitting right next to a happy phal); watered twice now (once a week) with mineral water/ very mild fertilizer. It is in a plastic pot with small-medium bark chunks. I don't see anything else in there. I have also misted it a few times this week with distilled water (happened to be in the sprayer) avoiding the flowers. Temps are normal household temps. Humidity is set to 50% on my humidifier in the next room.

I suspect it may have been hurt by the cold move to and from the car, or that I didn't water it in time last week. What do you think?