Payment method error

i just put pay pal as a default payment in virtual mart. But when i try to buy something from the site it shows Error: Please select a Payment Method. How to solve this problem ? When i click the check out button then it goes to step 1 shipping address step 2 ship methods then it goes directly to step 4.Then after it shows error message.But when i use my admin account for the shopping it works . For other who register their account is not working please help me out to configure this problem.