Ok, i read that RtmpDumpHelper is the same thing that "rtmpsrv". This one mounts all "rtmpdump" command automatically.
I tried with him and did not work because "rtmpsrv", after creates the the command with all parameters, automatically runs "rtmpdump" without delete that iptable rule:
"iptables -t nat -D ......"
So, i saved the command created by "rtmpsrv" and restarted the system and tried run the command as ordinary user. Look what i got:
For you see better the entire code.
http://pastebin.com/fR0NsADF
After remove this part of the command "-C S:7867 -C S: -C S:v-152 -C S:viewer -C S:anonymous-Brazil-3292 -C S:ed8a9da2c55f9f457ce5f0c529b1d3a7841d943f"
And replacing "d" for "b" in "S:3d4cc99358b21581f64c088d2ab6a6cd" like you did above.
Here( INFO: Connected... ), he stay a few seconds, 20 maybe, before shows the rest of the output.
http://pastebin.com/UA2rYS72