Are they sticky when you take them out of the oven? I have sticky tops if I put my cupcakes in a container after baking and cooling. Which I always do as cupcakes seem to dry out so fast.
When I'm ready to decorate, I take them out of the container and leave them sit uncovered for about an hour and that usually does the trick.
Its something to do with the sugar creating moisture but I don't know all the technical baking stuff as to why. I get sticky tops on my cakes too if I seal them up with plastic wrap. I do the same as I do with my cupcakes, unwrap the cakes, let sit to get air, and the tops eventually dry up nice.
Try leaving your cupcakes sit out on your counter without any covering for a while and see if that makes a difference.
Good luck! 
Joyfull4444- They come out of the oven sticky, and when I put them in the container I don't seal completely because of this. So if it's a sugar problem is there anyway to fix it?
PTBUGZY1 click on the link. Theres a host of information on why ones cake (which would include cupcake) did not bake up properly and how to correct it.
http://www.baking911.com/cakes/problems.htm
AI made macsmom's rootbeer float cupcakes last night and the tops are really sticky. Even after they have been sitting out. The insides are done so I'm not sure what the deal is. This is my first time using a box cake and adding more ingredients.
AI don't understand it though because the rest of the cupcakes are definitely baked enough. :-(
Thanks!
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