Sorry, but lack of familiarity with the basic constructs of your language of choice is definitely a bad indicator. Being a good programmer means more than just knowing how to do the things you've already done. You need to know your language, platform, etc., so that you can spot issues or create solutions. Fizz Buzz is only a stupid test because it is so easy. It sounds like you think the "ability to research and find solutions" means that you can find a solution to your problem to copy+paste off of Stack Overflow.
I heartily agree. There's no excuse for not knowing what mod is, even if you've never happened to need it in a program. I wouldn't hire someone who didn't know what mod is or couldn't explain it to someone else.