Have been trying to submit a site on and off for the past couple of days and keep getting a blank page. Tried with different browsers and its still the same.

http://add.yahoo.com/fast/add?148365

Try clicking the "Yahoo! Directory Submit" button.

Its working for me. Are you signed in with a Yahoo account? You'll need to sign in order to complete the process.

that link said category not defined within the process and that I should give details in my listing details. other than that everything worked like normal.