Aren't you supposed to use cedar wood when you smoke salmon? 
Cooking on cedar planks is not the same as using cedar wood to smoke.
"Bad wood. Whatever you do, never use wood from conifers such as pine, fir, cyprus, spruce, redwood, or cedar. They contain too much sap and that sap contains turpines, and they can make the meat taste funny. Some have been known to make people sick. Yes, I know that cedar planks are popular for cooking salmon on, but I don't know anyone who burns cedar as a smoke wood. I have also heard that elm, eucalyptus, sassafras, sycamore, and liquid amber trees impart a bad flavor. Oleander smoke is poisonous, and I am told laurel is too."
Amazing rib blog
