I've been also have this issue for quite a while too. Although the error I am getting right before rtmpdumphelper crashes is just
Code:
RTMP_ReadPacket, failed to read RTMP packet header
The crash happens in CB when models go private/group, on Naked when model goes offline, and on F4F when model goes private.
This was somewhat addressed here:
http://stream-recorder.com/forum/sho...&postcount=203
But I added that line and it didn't make a difference for me. Maybe there were more changes needed. I pmed Ito about it but I haven't heard from him in months.