[Icecast] ezstream upstream breaks on -SIGUSR1

[startx]

hello.

i use ezstream to stream to an icecast2 server, using a simple video
playlist of videos. 

in my ezstream xml, i re-encode the video with

<decode>ffmpeg2theora -x 192 -y 128 -a 0 -v 4 --title "@M@" -o -
"@T@"</decode>

however, when i use -SIGUSR1 as described in the manpage to skip the
current file and jump to the next in the list, the stream breaks and i
get lots of

    0:05:22.91 audio: 47kbps video: 15kbps, ET: 00:15:05, est. size:
    26.4 MB   error writing video page 
    0:05:25.92 audio: 47kbps video: 15kbps, ET: 00:15:05, est. size:
    26.4 MB   error writing audio page 

this breaks the stream.

this seems to come from ffmpeg2theora of course, but i can't see what
is causing this. the video files are all ok, and it happens with
whatever videos i have tried.

any idea what i am doing wrong?

startx