Lead Conversion Error - Access Denied

Hi All,

  I am facing a strange error with lead conversion for all roles. The role configuration is as below

 1. Step 2 - This has the below configuration
 
        a.HAS ACCESS/CAN CREATE/CAN READ ALL RECORDS for ACCOUNTS
        b.HAS ACCESS/CAN CREATE/CAN READ ALL RECORDS for CONTACTS
        c.HAS ACCESS/CAN CREATE for OPPORTUNITIES 

 2. Step 4 - This step has the below configuration

        a.Convert/Archive/Qualify  checked for leads

 3.The owner access profile has "READ/EDIT" for all 3 objects

 When I try to convert a prospect  (owned by me) with below set up I get "Access Denied" error. Cant we have the same contact linked to many leads?