no credit

wondering what to do -
a year ago my real estate agent friend ran a credit report on me and said i had excellent credit - last week he ran a credit report on me, because i would like to buy a house, and said i have no credit - i have had many credit cards over the last 15 years - have never paid a bill late - have never carried a balance over the due date - i paid off an $8000 stafford student loan in one lump sum in april of 2001, when it was due, and i paid off a best buy card in the amount of $2000 in full in june of 2001 and then cancelled the card. i currently have no credit cards and use a visa debit card that is linked to my brokerage account in which i have over 50,000 in savings. today i tried to sign up for two credit cards on line and was declined both times. yet when i requested a free credit report online the report indicated that i had good to very good credit. i'm pretty confused and concerned considering i thought i had been developing good credit all these years. any suggestions?