Yes, preferred account orders do get declined for no reason from time to time.. Known issue.. Aren't the first or last person to have it..
I'd suggest ending your preferred account and using a regular credit card to buy..
Otherwise, have fun spending weeks trying to get it resolved. NewEgg does have a line that you can contact for preferred accounts, though the payment authorization for the preferred accounts is handled by a 3rd party bank that NewEgg really can't do much to help you with.
I see so many complaints about the preferred accounts, the best advice anybody can give is to simply not have one.