Don't worry too much about it. I'm not sure how to spell it phonetically, so we can work it out in person if it bothers you.
I had dinner with a Phoebus once. He spent the better part of half an hour lecturing me on Greek pronunciation. I'm quite bad at it, I'm afraid, but the experience makes me understand the importance of what you're trying to do. Personally, I'm fine with an approximation.