You can have excellent credit and still be denied a loan. Yes, that is correct if you do not have enough documented income. This is espeically true if the buyers' income is commission based or is the result of getting residual income from the sale of a business. This is my the latest experience as a selling agent where buyers with excellent credit could not get conventional or portfolio financing.
Tightening rules and regulations make it tougher for newly independent business people and sales people to gain financing. Make sure you have enough time to have your commissions and income well seasoned at least 2 years before applying for a loan.
Otherwise, put your dreams of home ownership on hold until you have the necessary time under your belt or are able to pay cash for what you want.