Its becoming apparent that some soy companies aren't as safe as they claim. Some brands of soy protein isolate use hexane in their division of the soy protein. Yahoo published their own article on the story through this link http://shine.yahoo.com/channel/health/why-veggie-burgers-aren-t-always-a-healthy-choice-2341736
The company which made this report is cornucopia. And the http://www.cornucopia.org/2009/05/soy-report-and-scorecard/
Of course, the fact that some brands do not follow guidelines, does not necessarily mean that their disobeying USDA organic guidelines. If a brand of soy burger does not have the USDA certified organic seal, then it may contain hexane. This does not extend to tofu and soymilk of course, those forms do not use hexane.
Obviously they are aiming at soy...again. Studies have been conducted showing that the meat industry has been using hexane in foods for a long time now. But of course, they aren't under the light for that. As far as soy protein isolate, try to get the USDA organic approved