Unfortunately, it's not just a simple matter of trading bounties. You have to log in to near and hope someone random dropped a bounty that you need.
Best bet for finding the bounties you need is to replay the chapters where those bounties can be found (the bounty types available in each chapter show up on the chapter select screen). Basically for each chapter where the bounty type you are looking for, find the section in the chapter where there is the highest concentration of enemies to kill, and just keep restarting from the last checkpoint until you clear all the bounties available in that chapter. Unfortunately, some bounties are only available at specific difficulty settings (including easy, normal... and crushing - I don't think there are any bounties on 'Very Easy'), so you'll have to replay some chapters at different settings to find them all. This is how I found the last five or six bounties for my Platinum.
Add me too.
Also,has anyone else had a problem applying the last update after doing a DL from their Live Area??Mine DLed fine twice but started to load in and an error came up.What gives?I thought clearing it and DLing it again might help,it didn't.