[Dovecot] Segfault when using multiple servers

Should it be possible to run multiple dovecot servers on the same mailboxes (Maildir in my case)? I've a setup where 2 dovecot 0.99.13 servers write to the same mailboxes, which dovecot apparently does not like too much.

Example (using imap):

• Login with mail client on server1
• Login with webmail on server2
• Delete a mail using webmail on server2
• Hit send/receive in the mail client

Result: server1 segfaults.

Is such a setup, which is basically a loadbalancing setup, allowed at all by dovecot?

Cheers, Marc