Moving and upgrading Cyrus-imapd (howto) ?

[Jesper K. Pedersen]

In connection to upgrading our small email server (around 35 users) I 
have run into a slight problem. I can log into my server and also get a 
folderlist, but it seems it is hanging (not displaying) content in the 
folders.

My source server is running this version:
version
name       : Cyrus IMAPD
version    : v2.2.6 2004/06/17 18:54:31
vendor     : Project Cyrus
support-url: http://asg.web.cmu.edu/cyrus
os         : Linux
os-version : 2.6.11.11
environment: Built w/Cyrus SASL 2.1.18
             Running w/Cyrus SASL 2.1.18
             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 0.9.7b 10 Apr 2003
             Running w/OpenSSL 0.9.7b 10 Apr 2003
             CMU Sieve 2.2
             TCP Wrappers
             mmap = shared
             lock = fcntl
             nonblock = fcntl
             auth = unix
             idle = poll

Destination:
version
name       : Cyrus IMAPD
version    : v2.3.1-Invoca-RPM-2.3.1-2.6.fc5 2005/12/20 15:54:43
vendor     : Project Cyrus
support-url: http://asg.web.cmu.edu/cyrus
os         : Linux
os-version : 2.6.15-1.2054_FC5
environment: Built w/Cyrus SASL 2.1.21
             Running w/Cyrus SASL 2.1.21
             Built w/Sleepycat Software: Berkeley DB 4.3.29: (February 
15, 2006)
             Running w/Sleepycat Software: Berkeley DB 4.3.29: (March 
24, 2006)
             Built w/OpenSSL 0.9.8a 11 Oct 2005
             Running w/OpenSSL 0.9.8a 11 Oct 2005
             CMU Sieve 2.3
             TCP Wrappers
             mmap = shared
             lock = fcntl
             nonblock = fcntl
             idle = idled

My procedure for migrating to the new server was stopping the source 
server. Finding all files that were running the Berkeley format and 
making a new file using the cvt_cyrusdb to make a new skiplist format file.
I then used rsyns to copy all the files to my new server (keeping its 
location in the filesystem the same). I copied the imapd.conf and the 
cyrus.conf over (with a few adjustments to give support to sql 
authentication backed).
As a final step I converted the skiplist files back to the new Berkeley 
database format and started the server.

Anyone with any ideas what can be the problem... Or even better - what 
is the correct way to migrate Cyrus-Imapd from one version to another?

Thanks,
  Jesper K. Pedersen