This might just be a coincidence, but after reading DOL is eliminating the pre approved labor, I notice that the people who got LUD on I140 has SUB labor. I suggest you check with your lawyer to make sure everything is OK.
My friend's lawyer was hesitent in using the pre approved labor for him after the PERM processing started. As per him USCIS/DOL is recommending to withdraw pending approved labor prior to cases moved to back log reduction center to eliminate the fraud. I also checked some other thread for this information.
www.immigration-law.com