I too go on short int'l trips (two or three days), but I have yet to be grilled (perhaps now I have spoken too soon ). I'm not sure why this is the case, but I have a feeling it's because I'm male (asian), dressed in business attire, and I have a Multiple Entry US TN-Visa attached to my passport (like many others have). Although the TN-Visa has absolutely nothing to do with a non-American work trip, I think this gives them some notion that I'm pretty safe anyway. I even pack extremely light (just one knapsack) and that always raises their eyebrows (That's all you brought?) I hate to say this, but I do feel that some of them single people out based on certain "demographics" which sucks, but I guess it's part of reality of the world nowadays...

Only one time (over several hundred trips) have I been directed to secondary at YYZ (arriving from IAD). When that happened, I think the Customs agent didn't see my TN. The woman at secondary was quite harsh, but I answered my questions with a challenging confidence and flashed my work visa. Luckily for me, she didn't further the questioning and I didn't have to unpack all my crap and explain everything in detail. No problems at all with short int'l trips (yet).

What I find disturbing is that they direct my female colleagues much more to secondary. From my discussions with them, they are always questioned about "purchases" that they didn't even make. God forbid, but is it not possible that a female who went abroad for work DID NOT go shopping once over a span of four days? And is not possible that they actually did travel for work?