Hi johndoug,
I'm no expert and haven't grown corn for awhile, but it sounds to me that they aren't getting fertilized well enough. I know you should grow a certain sized block of corn, to make sure it gets fertilized, but I forget the dimensions. There are also ways for you to try to fertilize the cobs yourself.....but I'll leave it up to the experts to tell you how.

P.S. about the zuchinni.......for me, it really varies from year to year. They need water, like all plants do. But they can get cucumber beetles that cause wilt, and can get squash borers, which all can contribute to an early demise. My plants are still making a couple zuchinni, but they are definitely not looking so great. Also......be sure to keep the big ones harvested, even if you don't want to use them, 'cause that will cause the plant to not make new ones.

I'm no corn expert, but it sounds like probably lack of pollination. I have picked corn from my small patch that is about mutant looking, and some that has nice straight rows and full ears. You're supposed to plant at least 4 rows wide for decent pollination. I'd try for more though, I planted about a 4' x 5' block, but not all of my seeds germinated well, so there were some real gaps. I think that's why I got funny looking corn.