I have not found made in the USA Tri-X in 35mm or 120 at any Boston-area or Washington-D.C. area camera store - except for Calumet Photographci - since late 2003. Not even good-sized chains like Hunt Photo and Video in Boston or Penn Camera in D.C. In the past 12 months I haven't done any real retail buying, so this may have changed again. But I noticed the 400TX on sale at my local Best Buy, recently, was not made in the USA.
Odd, since nowadays Kodak only has coating facilities in the United States. There is no way Kodak can coat any type of film other than in the USA, however it seems ALL Kodak films (in 35mm) are finished in Mexico..that is cut and loaded into cassettes. Is that what you are seeing? That is not Grey Market.