I have 2 pumkins right now, and I used one and it worked. I tried using the other pumpkin but it told me I had to wait another 24 hours. Aren't they supposed to have separate timers? EDIT: One of them in my chest worked though.
Were they stacked when you used one? I've found that this is an issue, it has been added to Track. http://track.empire.us/issue/EMC-356
They were in seperate chests. You can see what I mean at 1148. I took each out in the same stack though.