[Dovecot] Dovecot LDA (deliver) stopped working

[falz]

Hello,

One day a week or so ago, a server that's Postifx w/ Local users,
dovecot w/ LDA decided to stop working. The only thing that stopped is
the LDA portion, the rest all works fine. I also posted to the postfix
mailing list yesterday but wasn't able to debug any further. Here's
the situation:

if I use mailbox_command to point to deliver, postfix will always put
the message in the deferred queue. However, if I run deliver from the
command line, it works fine. I've recompiled Dovecot and Postfix
cleanly and reinstalled a few times to ensure permissions are OK. It's
not a virtual setup, so I do NOT have setuid root on the deliver
binary.

Postfix people suggested placing a wrapper script for mailbox_command,
which I did, and have it log to a text file, so I do know that deliver
is being called. However, although I have LDA debug logging on, and it
DID log prior to this, when postfix supposedly calls deliver, dovecot
does NOT log anything. It DOES however log if I call deliver from any
account (root or not) from the command line (ls / | /path/to/deliver
-d localaccountname). Any way I can debug this further? I would assume
that deliver would log something even if it's called, but it appears
that it does not.

My postfix related details are here:

http://marc.info/?l=postfix-users&m=120119147917409&w=2

I followed the postfix/lda wiki (http://wiki.dovecot.org/LDA/Postfix)
when setting it up, and it worked perfectly for months. I did indeed
only have to change mailbox_command and it worked (I'm also using sasl
auth, but that should be unrelated). Obviously something happened on
my system, but I would assume recompiling/reinstalling would reset
things. Nothing in the config files for postfix or dovecot changed,
from what I can see, as generally I am the only one making changes.

Thanks,
--falz