Mj2 Stopped Working

On one dedicated server (Linux Fedora, Apache2, Sendmail, Ensim control 
panel), I have Mj2 installed on four domains. These are separate 
installations. All have been running for at least two years.

One installation stopped working. Three continue to work just fine (quite a 
few lists with from 6 to over 600 subscribers each).

On the one that stopped working, what I mean is that list mail doesn't go 
out and requests for help topics don't get answered. Regular mail on that 
domain is working fine. A few Majordomo 1.94.5 lists are working fine. The 
Mj2 lists -- two of them, with 33 and 92 subscribers -- just stopped. 
However, I can create a new list and Mj2 will send me a "mailing list 
created" notification immediately.

If I run mj_queuerun from the shell, it times out after about two minutes 
(at least that's the message I get), and nothing is sent.

I updated the installation two or three days ago with the 
majordomo-current.tar.gz from the mj2.org site. Didn't help.

Okay, one more thing. Now and then, I can get the mail going again by 
cleaning out older files in the mqueue.site directory. This folder is used 
rather than the mqueue directory when MailScanner/ClamAV is activated. I 
don't know why that helps because as I said all regular mail, and there's 
quite a bit of it, is being delivered just fine. It could be that the Mj2 
mail is getting stuck there. However, and perhaps this is some sort of clue, 
I cannot "see" the contents of the files left in mqueue.site because for 
whatever reason they all are binary files and viewing them results in a 
bunch of jibberish, of course. Still, the set-up is identical to the other 
domains where Mj2 is functioning just fine.

Anyway, should I perhaps completely uninstall Mj2 and start over? Is there 
something I can look at or try that may tell me what's going on?

Dean Collins