dovecot - May 2015 - Imap process timeout to quota proxy on logout after async commit

Hi there, I am having some trouble implementing a quota proxy server for a
memcached based dict (I am using the version 2.2.15).
I created a multi-threaded daemon that is using non-blocking sockets to receive
the data and reply to dovecot. Right now everything but the atomic increase
message is working great. Here is an example of such a message:
B1
A1??? priv/quota/storage??? 86583
A1??? priv/quota/messages??? 1
D1

The program process it and I replies:OA1

Everything keeps working as expects until the user sends the imap a logout
command.? The only problem is that for some reason dovecot tries to read data
from server without sending anything, and after 30 seconds it exits with an
timeout error. The following message is logged:
May 18 22:46:00 imap[11654]: user 29908633#perm!terra (29908633#perm!terra) from
127.0.0.1: Error: read(/tmp/quotatest) failed: Timeout after 30 seconds
May 18 22:46:00 imap[11654]: user 29908633#perm!terra (29908633#perm!terra) from
127.0.0.1: Info: Disconnected: Logged out in=40 out=827
May 18 22:46:00 imap[11654]: user 29908633#perm!terra (29908633#perm!terra) from
127.0.0.1: Error: dict quota: Quota update failed, it's now desynced

The really strange part is that it only fails if and atomic increase was sent
and only when the user logs out.
I use the same pattern ("OA<transaction id>\n") to reply for
other commits (such as when there is an unset followed by a set) and there is no
issue.

Is there anything that I am missing?
Thanks in advance.