DCOM thru FW-1 NG AI R54

[watcher60]

All,
in a test lab I've been asked to allow dcom from a win2k3 server in the DMZ zone to another windows server in the LAN. Although I've even gone to the extent of allowing any any either way between these two segments (with the Fw-1 NG AI R54 inbetween) it still fails. I have noticed shortly after the intial connection on TCP 135 there is a totally blank drop line in the logs. Bar the drop, date and time field the only other detail in the line is that it is on the DMZ interface. I'm at a loss on how to proceed on this as it does seem that the firewall is dropping a packet in the DCOM communication but as there is no information or even rule number I can't see how to troubleshoot this. Can anyone shed any light on this?

many thanks