If you have an adjustable dampener in the chimney, make sure that it is open fully. Also, as previously posted, when last did you get the chimney cleaned? How do you know that a bird did not build a nest in the chimney during the summer, or maybe even die in the chimney?

 

Are you using a grate or are you placing the logs directly on the brick?
I use a fire grate and make sure the ash is cleaned out from under there. that way the air drafts up from underneath and I get a nice warm fire going....

 

Yes, there is a grate in my fire place and there will be a nice bed of coals and ash, but I clean the ash out before it builds up to the grate.

 

in your travels watch for a construction site. somewhere around there will be a pile of scrap, root through the pile for the 2x4 saw cuts. unless you live in a really wet climate these should be reasonably dry. split them and see if you still have the same problem.
If you have the same problem, there is a fireplace issue, if you have a warm toasty fire you have a wood issue....
10" diamater logs seam pretty big to me and most certainly big if your wood is green....