A yellow bar appears and blocks Flash link when "_blank" target is used to open the link in a new window.
TEST
SOLUTION 1
Open your project, choose Movie > Frame Rate and change target player to Flash Player 8, click OK

SOLUTION 2
If Flash Player 8 or above is not accepted, use On Up action to launch links instead of On Click action. Make sure On Click action is disabled. The URL will pop-up when mouse button is released.

If clickTag (banner tracking) must be used put the code in On Up dialog:
