We just had a new elementary building constructed this past year. They
installed 3com 4200 series switches in the building and now when I try
to multicast an image, the workstations don't detect the master.

There is also a Superstack 3226 in one our old buildings and whenever I
try to multicast computers that are plugged in to it, the same thing
happens. I've went through and tried to disable every filter setting I
could find, but nothing has changed.

Do the IGMP query and snooping modes cause this if they are enabled or