whats wrong with my voodoo lilly (amorphophallus bulbifer)

i started a plant form seed about 4 weeks ago and the leaves are starting to curl inward. i have it in a little pot, on the window sill in the kitchen. i have it in standard potting mix, i keep the soil moist, it gets moderate sun. i pot a thin 1/8" later of compost on top...is that what i did wrong???????

Sometimes Amorph leaves curl when they are grown in low humidity.

Cody, here is some care info on your A bulbifer

http://www.rareflora.com/amorphophallusbul.htm