SH> Eventually I changed another line for another conference to
 SH> point to that conferece, and the messages show up - but then
 SH> the first conference disappeared. It seems that what is
 SH> doesn't like is the echotag.

so, what is the echotag?? since you mention it but you don't tell us what
it is, your next question...

 SH> Can anyone suggest what might be causing this?

makes absolutely no sense at all...

OB-)

)\/(ark