This is a follow-up to a previous post:
http://www.cougarboard.com/board/message.html?id=7725465

True to the past, we had no problems for the 3 weeks since that post until yesterday when the wind picked up a little (this is Northern CA- nothing like the winds in Utah), and today I can't keep the pilot light lit for more than 5-10 min at a time. I have re-lit it at least a half dozen times today already.

Now, I don't think this is the thermocouple for the following reasons:
- Each time I go out to re-light the pilot light, there is a faint smell of gas that dissipates. This indicates to me that the thermocouple is closing the valve AFTER the flame has already gone out.
- I watched the flame today until it went out. It went out when the full burner was lit. I heard a small gust of wind in the duct work, and the flame (pilot light and all) looked like it suffocated itself out. I did not feel any draft around me or the water heater when this happened.
- I cleaned the air intake as best as I could (which wasn't very good because I couldn't get very far under there with the vacuum or a brush because it was so tight). It didn't look very dirty, though.

Based on this, I am convinced that it is the vent installation and is not the thermocouple. I think the wind is preventing the exhaust to vent out, and that is preventing new air from coming in, so the flame runs out of oxygen. Does this logic sound right?

Now, I am still unsure what to do about it. It looks like there is already a high wind cap installed on the vent. It only happens when the wind is coming out of the north. I'm afraid this is going to get expensive.