Viking and White- I agree with the wind thing. It only makes sense, every wild animal uses its sense of smell. I also don't doubt that it could ever be cold enough to suppress the Gusto, I could smell it today at -10. I pretty much carpet bombed this drainage with 6 sets and the bugger came close to 3 of them. I'm sure he will get into one of them eventually. I have faith in all 6 of my sets in that area.
Boco- right now all i have for bait is chicken legs. My buddy did just get 3 beaver and a whole mess of pheasant, so I will be using fresh beaver by weeks end in at least half my sets. Going to try pheasant wings tied to a limb in front/above my box sets to maybe give a visual cue.
The tacks were mostly straight line, but were in relatively open area. The set he passed twice is 50ft off an old spur road along a relatively open ridge line. Thicker with large spruce, lodgepole, and douglas fir on either side. Once the tracks reached the trees they started to zig zag a little.