I'm sorry if this has been addressed elsewhere -- I looked, and the incense forum is rather small. (So I'll be even more embarrassed if it has been covered, of course.)
Since I'm focusing on learning ceromancy and doing candle work right now, this caught my interest. I had just cleansed my altar space thoroughly, replaced everything, and started burning a small cone of All Saints Incense. I looked over everything and said, "Look at that, all spanky clean." All satisfied and whatnot.
Then there was a loud "pop" from the incense, and ash blew all over my freshly cleaned space.
So I wiped off the ash, sprayed and wiped the surface again with dilute Florida Water, and added a little more incense to the pile. But, um? Is this common? I've never had this happen with incense.