A question about Majordomo

Hi, everybody.

I've been using Majordomo 1.94.5(on RedHat 8.0) for more than 2 years. It
had worked perfectly. But a week ago there's a strange behaviour of
Majordomo that's  unbelievable. Well, the problem is that:

 1. the bounced mail which included the undelivered addresses of list's
members was sent to each members. It mustn't be that way. Such a mail should
have been sent back to the administrator of the list only, shouldn't
it?..not only that,hundreds of mails get sent repeatedly(in loop).

Or might there be something to do with qrunner? because at that time, there
were more than 500 mails queued. Eventhough I've tried to delete them
manually,there were always  new ones get queued. At last i decided to stop
sendmail and rebooted the machine, and then thing went normal again. Spammer
abused the list?!..i have no idea.

Would please help me to trace the problem?

best wishes,
vanny