[Dovecot] Running two different versions of Dovecot (was: making folders unmovable)

[Dave]

OK, so I decided to go ahead and just upgrade to the latest 1 series 
Dovecot and see if that solves my ACL/config issues I've been having. 
(I tried compiling 2.0.9, but it errored out and I assume that's because 
it's a pretty old machine/compiler.)

Anyway, 1.2.16 compiled fine, and I installed it in another location 
from the currently running 1.1 series install.  I have this new install 
running (IMAP) on a non-standard port while I test it out, and it starts 
fine and all seems well.  However, I'm wondering, is it OK to run it and 
have it look at the same Maildir mailboxes as the currently running 1.1 
series install?  Does that have the potential to mess with indexes or 
change anything in a bad way?  (FWIW, I tried it briefly, and after 
changing the port number in and restarting my mail client [Thunderbird], 
it had trouble pulling up the mailbox I was trying to access.)

David