High bitrate /live stream publish and playback issue

Hi, we are publishing a live rtmp stream to /live application. At low bitrates < 1mbps, playback is smooth. Around 2.5mbps issues get noticable, and at 5mbps stream is not playable - cannot play 2 seconds of video straight.

This is being tested on a local network, 1 publisher and 1 viewer, FMS 4.5 being on redhat 5.

Wireshark capture shows a lot of delay between audio packets and video packets. When audio packets are at time 27.0, we see video packets at timestamp 8.0 (~20 second delay).

We tried to turn off agrregate messages, live queue, et al according to

http://help.adobe.com/en_US/flashmediaserver/configadmin/WS5b3ccc516d4fbf351e63e3d119f2925e64-7ff0.html#WSd4da1475f4e0dbda-2663a64312a19f4f1cb-8000

but found no improvement in the streams.

Looks like a simple remux problem. Does anyone have any idea about this issue?

Thanks.