problems with mailing list

I am admittedly a majordomo newbie and I'm having trouble with a certain
mailing list.

In short, I have an list that has 124 addresses in it, mine including.
Emails sent to this list are not delivered.  Emails sent to other lists are
delivered fine.

As a test, I removed all but my address from the list and sent a new email
to the list. This was delivered immediately. As far as I can tell, the only
difference between the two lists is the number of members they contain.
Should this make a difference?

Like I said, I'm a newbie to majordomo so I'm not sure what to try next.

Here's some info from my system:
majordomo verion = 1.94.5
OS: FreeBSD 3.5-STABLE
Perl version 5.00503
mail_version = Postfix-19991231-pl08

Any ideas or suggestions would be appreciated.

Thanks!

Andy