Failed to update header with correct duration.

So I'm progressing using avconv to create an archive mp4 file as well as stream to a rtmp server.

Stopping Capture 22 q=28.0 q=31.0 size= 5138kB time=62.48 bitrate= 673.6kbits/s
Failed to update header with correct duration.0kB time=62.96 bitrate= 672.7kbits/s
[flv @ 0x248b7c0] Failed to update header with correct filesize.

It starts up, works, then dies with the above error.

Here's the command line I'm using:

bmdcapture -C 0 -m 14 -V 3 -A 2 -F nut -f pipe:1 | avconv -y -i - -c:v libx264 -c:a aac -ar 44100 -strict experimental -s 640x360 -b:a 160k /pub/video/"$SHOW"_$TIME.mp4 -f flv -c:v libx264 -c:a aac -ar 22050 -strict experimental -s 384x216 -b:a 64k rtmp://live.mysite.com/myapp/video

Can anyone explain what this means?

I can capture, or I can stream, but it seems when I attempt to do both, I have problems.

Thanks