It definitely seems to be an issue and I've felt it at the point of hiring. When I was looking for a job in 2011 I interviewed at one company and had, I thought, a series of very good in person interviews with people at a location in the DFW area. They seemed very pleased with my experience and with some of the specific technologies I had used which they needed help with.
However, I was told first that I would likely get an offer within the next couple of days and then suddenly that I needed to do an additional phone interview with someone in CA. I did that interview and I was killing every question the guy had, but I said something about floppies or who knows what in one of my answers and the interviewer came back with, "How OLD are you?!?" After that he wrapped it up in two minutes and I was told by someone who worked inside the company that they were overruled on hiring me.
Very similar to what I encountered recently interviewing with the local "cool" tech start-ups here in the Atlanta metro area. Great phone interviews and coding tests but when they saw the gray hair and wrinkles in person I was shown the door quickly.
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