This happens a lot. When I first started trying to contribute to an OpenSource project years ago, what I would do on IRC is message the main developer. Then the main developer would say "Why is this conversation private?", then it would move into the channel. This makes sense. The same thing is true for e-mail. I often get e-mails about the project from someone who is working on something, and they'll have an opinion. Sometimes the opinion is one that I agree with, but most of the time it's one that I don't.
Now, since someone e-mailed me personally about a question regarding what I'm doing on an open source project, I'm more than happy to ignore them, and to not fix their problem because I work for either myself or my employer on the project, not for them. Decisions made in private on a project are ones that I won't easily entertain unless it benefits me. Now, if they were to actually post to the list their problem, while I may disagree with what they want, the other contributors may not, and there may be some other committer who is willing to champion their change, and I may be convinced. I will also have to respond to it because there are other people watching the list keeping me honest. Finally, it allows for more project transparency, and doesn't come off as insulting or rude when I check my inbox first thing in the morning.
So, please, if you have a question about code that I'm working on for an Open Source project, PLEASE post it to the public mailing list. That way, it's less likely to be ignored, and you sound like less of a jerk. I think this is an importnat piece of netiquette that is too often overlooked.