problem with Cyrus 2.1.9 on tru64unix

[Marco]

Hi all,
we have installed and setup cyrus-imap server 2.1.9 with cyrus-sasl 2.1.7
on a compaq ES45 with tru64unix, we have used berkeley db 4.0.14
the problem is that sometimes the master freeze, the socket on port 143
is open but the master doesn't answer and we get a connection time-out,
in the log we have nothing that can explain this behaveiour,
we then decided to try an upgrade installing cyrus 2.1.10 sasl 2.1.9
e berkeley db 4.1.24NC with patches from 2 to 6.
Now it doesn't work anymore if we run ctl_mboxlist we get this error in 
cyrus.log

ctl_mboxlist[357567]: DBERROR db4: unable to join the environment
ctl_mboxlist[357567]: DBERROR: dbenv->open '/var/imap/db' failed: 
Operation would block


we have also tried to  install cyrus and sasl compiled first with shared 
library
and then with only static library but in both two cases we didn't solve 
the problem.

Any help?

Best regards
Marco De Simone