I'm very new to smoking, and I've learned a ton here in this forum. I figure I'll share my few experiences. So far, no AMPNS, although I'm pretty certain I'll buy one, for the convenience if nothing else.
I've smoked several times since getting my 20070311 unit just before Thanksgiving. All have gone great, but I did have two fires this past weekend. When I examined the chip pan, I found that it has only one screw in it (should be four) and so the right side is drooping down. I folded some aluminum foil several times to get a height to match the left side and inserted the foil to help hold up the right side. I also added a screw in the back left side (can't access the right side screw holes).
I also closed the vent this time while adding chips. I let the chips get going, then later opened the vent. No fire! I think the key for me is to reduce air flow while starting the chips, and then open the vent later.
I never add water to the pan, but every single thing I've smoked has come out tender and juicy. I don't think you need to add moisture. In fact, as people here have said, it'll work against you. I liked Foamheart's comment about the vent and loader, with relation to chips or pellets.
I've smoked two hams. The first one was good, the second one was superb and had some bark. I've smoked wings several times, chicken several times, brisket once (want to do that more), and a few salmon. I really want to smoke a pork butt. I also need to learn to take photos of my smokes!!
This is one of the most fun hobbies I've taken up, and my whole family enjoys it, LOL! Lots of experience on this forum, and yeah, they may go contrary to the manual at times, but they're artists learning to use and share their knowledge. I'm one of those guys who wants to learn more and learn "why" I do something or why the smoker does something, in the hopes that maybe, just maybe, I can have a repeatable process! :-)
Good luck and have fun!