I've also heard them used interchangeably. And have heard the "7 pots of food" thing, too. "7 pot" makes the most sense to me, as the story seems plausible. I can't come up with a good reason to use "7 pod" - the plant only puts out 7 pods? No. Ummm.... you'll give up after eating 7 pods? Maybe, maybe not. I tend to agree that "pod" was probably a misinterpretation, but of course, that's just in my way of thinking.