Subprime wholesalers looking to grow their businesses by expanding their mortgage broker networks could be in for a rough ride: a new survey sponsored by Inside B&C Lending suggests that many brokers are reluctant to work with new lenders. The national poll of 1,800 brokers, conducted by Washington, DC-based Campbell Communications, highlights a number of potential challenges – and opportunities – for subprime and Alt A mortgage wholesalers. Chief among them, the thorny issue…