This just in, from the Department of (Slightly) Useful Factoids:  cinnamon inhibits the growth of yeast.  So if you want a cinnamon flavored yeast bread (like cinnamon rolls, or cinnamon-raisin bread), use it sparingly and add it just before shaping.  Best to give the yeast a chance to develop before introducing a potential deal-breaker.

Now, back to your regularly scheduled programming….