Why am I getting frost/ice in the top half of my GE Profile freezer?

I have a GE Profile refrigerator model PSS25MGMA WW that I keep getting frost/ice forming on all the food and in the ice maker in the top section. I checked the gaskets, which seem fine. It does appear to defrost every so often as I will open the freezer and find moisture on the inside and the ice cream will get soft. Then it will freeze up again. I have tried removing all the "frosted" food and emptying the ice maker and drying it out with it only to return. I also stuffed a rag in the ice dispenser to try to troubleshoot that door to be the culprit. thoughts or next step in troubleshooting?

thanks in advance!

Matt