Not all mailboxes listed when migrating to new server

[Keith Edmunds]

I am migrating a Cyrus IMAP server to new hardware. To
migrate the accounts I did the following on the old server:

ctl_mboxlist -d > /tmp/mailboxes.dump

...and on the server:

/usr/sbin/ctl_mboxlist -u < /tmp/mailboxes.dump
/usr/sbin/cyrreconstruct

(This is a Debian system, so the "reconstruct" command has
been renamed).

From inside cyradm, a "lm" lists about a quarter of the
mailboxes (that's a guess; if it's important I'll find out
how many), yet the directory structure within the Cyrus
partition appears to contain all accounts.

If I do a 'lam user.xxx' where user.xxx is one of the
accounts not listed, I get 'Mailbox does not exist'. If I
send a mail to that user on the new server and repeat the
'lam user.xxx', I get a blank line output, suggesting that
the mailbox does now exist but with no acls. The mail sent
to that user can be seen in the filesystem.

Can anyone shed any light on what is happening here?

Thanks,
Keith

Versions:
Old server:
name       : Cyrus IMAPD
version    : v2.2.10 2004/11/23 17:52:52
vendor     : Project Cyrus
support-url: http://asg.web.cmu.edu/cyrus
os         : FreeBSD
os-version : 4.11-STABLE
environment: Built w/Cyrus SASL 2.1.20
             Running w/Cyrus SASL 2.1.20
             Built w/Sleepycat Software: Berkeley DB 3.3.11: (July 12, 2001)
             Running w/Sleepycat Software: Berkeley DB 3.3.11: (July 12, 2001)
             Built w/OpenSSL 0.9.7d 17 Mar 2004
             Running w/OpenSSL 0.9.7d 17 Mar 2004
             CMU Sieve 2.2
             TCP Wrappers
             mmap = shared
             lock = fcntl
             nonblock = fcntl
             auth = unix
             idle = poll


New server:
name       : Cyrus IMAPD
version    : v2.2.13-Debian-2.2.13-10 2006/11/13 16:17:53
vendor     : Project Cyrus
support-url: http://asg.web.cmu.edu/cyrus
os         : Linux
os-version : 2.6.18-6-686
environment: Built w/Cyrus SASL 2.1.22
             Running w/Cyrus SASL 2.1.22
             Built w/Sleepycat Software: Berkeley DB 4.2.52: (December  3, 2003)
             Running w/Sleepycat Software: Berkeley DB 4.2.52: (December  3, 2003)
             Built w/OpenSSL 0.9.8c 05 Sep 2006
             Running w/OpenSSL 0.9.8c 05 Sep 2006
             CMU Sieve 2.2
             TCP Wrappers
             NET-SNMP
             mmap = shared
             lock = fcntl
             nonblock = fcntl
             idle = poll