Did you activated the folder redirection for these folders?
How to do this:
" In the messages goto "Options".
" Then select "Email settings"
" Now click on the wheel and select "Folder Redirection"
" Click on "Mailbox username" and select expand
" Click on "Inbox" and select expand
" Click on the folder you want to sync with your BB and select "Change Option"
" Repeat this last step for every folder you want to see on your BB.
" When all folders are selected, click on the wheel and choose "Save"
How to view your extra synced folders:
In the messages goto "View Folder".
Then select the folder you want to view.