I believe the problem with exporting a vehicle from Canada with a BC reassigned VIN stems from several years ago when people were using the reassigned 17 digit VINs to bring JDM and other vehicles into the USA from Canada that were not eligible for import. Basically with the reassigned VIN these vehicles appeared on paper to be original to the North American market and exempt from the USA 25 year import rule. I dont know if it was the Canadian or USA side that caught wind of it and put a stop to it. Since then BC has stopped reassigning VINs on JDM imports.
dadio13 any chance you still have the original Canadain vehicle import form (Form 1) that shows the original VIN? Or the ICBC paperwork showing the original and reassigned VINs? Either way I would contact CSBA (Canadian Border Service Agency) and The US Customs and Border Patrol and explain to them exactly your situation and see what they have to say. Dont go by word of mouth or what someone at a registry office might think.