Yes, I did have this experience. Made a trip to Silicon Valley to talk over a licensing agreement with a tech giveback (by us). One of the ideas was shot down by a senior tech guy there as "unworkable". We (stupidly) dropped the idea after being ridiculed for it.
More than a year later, he and the head of their marketing took at exact idea, created a company around it, and later sold it for more than 230 million.
Why do they always have to have politics in these sorts of things? I don't care if you're an Obama supporter or a Palin supporter, but putting stuff like that in a site like this just ticks 50% of the people on your website, because you're making fun of "their man" or "their woman".
Age shouldn't be an issue, but it is. I've worked with many young developers that think anyone over 30 doesn't have a clue.
The real problem is that some developers over 50 refuse to learn new things, and that gives younger folks a tainted view of all older developers.
Frankly, getting older and having the potential of getting discriminated against because of my age scares the crap out of me. No way to prove they're doing it, and never to be hired again, at least as a full timer. Yikes.