Icecast - Nov 2005 - 100 percent CPU utilization while sourcing a Speex stream

I mentioned in a previous post about being fooled that something was
wrong because using ezstream (or any other libshout2 client) to
stream a Speex file completed really quickly.  Well I think the
problem is that for some reason icecast 2.3.0 is not handling things
well, at least not compared to the other stream formats.  I see now
that it is using 100% of the CPU when being sourced a Speex stream.
If I source Vorbis, Theora, or MP3 streams the icecast server remains
with a fairly innocuous utilization. Maybe related, most likely not,
looking in libshout I'm suspicious of this code:

void shout_sync(shout_t *self)
{
        int64_t sleep;

        if (!self)
                return;

        if (self->senttime == 0)
                return;

        sleep = self->senttime / 1000 - (timing_get_time() -
self->starttime);
        if (sleep > 0)
                timing_sleep((uint64_t)sleep);

}

Why is senttime being scaled by 1000, is it in different units than
starttime?

Suggestions welcome.

William.