[Dovecot] shared folder

[T. Horsnell]

The dovecot wiki says:

The only way to implement shared folders with Dovecot 0.99.x is to 
create a "shared userid" which all of the users log in to read mail.

Does this mean that folders owned by that shared uid can be
*simultaneously* manipulated by multiple users logged in to
that shared uid?
This doesnt seem to be the case on my dovecot-0.99.11-4.EL4
system, and before investigating further I just wanted to
check whether it should be possible or not.

Cheers,
Terry.