Problem with PRI interface

We have a Cisco 3745 router running IOS 12.2(15)T12. It has a PRI interface on it and we have several dialers set up. I enabled netflow on only the fast ethernet interface on this router initially but noticed that Netflow Analyzer saw all the dialers on this router. After a while we noticed that Netflow Analyzer was only showing outbound traffic for all the dialers. I then put the "ip route-cache flow" statement on one of our dialer interfaces. I then noticed that when i did "show ip cache flow" any traffic originating from that dialer showed as source interface s4/0:8 but any traffic going to that dialer shows as destination interface di0. The s4/0:8 is the actual physical interface and subchannel of di0. Therefore we now have 2 interfaces showing in Netflow Analyzer both representing di0 but one shows only the outbound traffic and the other shows only the inbound traffic. Do you know any workaround for this? I thought id ask you guys before i start trawling through the Cisco site.

Thanks

Mark