Ed - The problem, for lack of better words, that I had was the suggestion by jc and yourself that there's nothing to worry about. Go ahead, even though you're not a hvac tradesman and make your comment, but qualify it with something like, "If I was 'you' which I'm not but if I were, I wouldn't worry about it. But for peace of mind, it wouldn't hurt to have it checked out." Of course, you can say what you wish from YOUR perspective, and jc's for that matter, but I was a bit distraught to read that it was a RELAX and an Exactly RIGHT as a response. Yes, we all seem to agree that it's condensation, agreed? But remember your audience. They wouldn't be posting questions here if they weren't concerned to begin with. You are you, and they are them. I don't care if I get the CALL at 6am saying they don't have HW. But I'm sure they'd rather get a qualified answer for peace of mind when they aren't in the middle of the 6am rush.
Because the poster posed the question, I can see her going to her husband and saying, "Honey, 2 people on renovateyourworld.com said it's probably condensation and we should RELAX." That's a good and educated guess but like I said, I can't see it from here, and neither can anyone else for that matter. Nough said.