lmtp socket error

[Shaw, Brian]

All,
   I'm not sure if this is a cyrus error or a postfix error but, I can't 
find any information about how to resolve it.
   I'm seeing the following in /var/log/maillog:

Jul  1 21:52:15 mail-server cyrus-imapd/master[11907]: process 
type:SERVICE name:lmtpunix path:/usr/lib/cyrus-imapd/lmtpd age:0.206s 
pid:12140 exited, status 75
Jul  1 21:52:15 mail-server postfix/lmtp[12036]: EB0C1E5B11: 
to=<user at example.com>, relay=mail-server[/var/lib/imap/socket/lmtp], 
delay=32177, delays=32169/6/2.6/0.02, dsn=4.3.0, status=deferred (host 
mail-server[/var/lib/imap/socket/lmtp] said: 421 4.3.0 lmtpd: Internal 
error: assertion failed: lib/cyrusdb_twoskip.c: 600: record->level <= 
MAXLEVEL (in reply to end of DATA command))

   The really strange thing is some mail goes through and some does not.  
I haven't found any pattern to it yet.
   Any suggestions would be greatly appreciated.

Brian