Guys,
You may encounter a situation when no traffic is being exported on R1 even if traffic export is applied correctly.To be precise not traffic is matched by ACL.
Fix:
Try to ping in reversed direction. In my case ping from R6 to R5 was not caught by FILTER access-list (no matches). But once I pinged from R5 to R6 via R1 (I shut down some interfaces on R4 and R5 to make path straight via R1) it started working and FILTER access-list on R1 matched that traffic.
You may also notice a significant slow-down for ping traffic (exporting takes resources)
Tom