[exim] Failed to read delivery status

I just updated to Exim 4.8 and have an issue I had never before with delivering incoming emails. When the local_delivery is set to file everything works fine, mail is delivered. But not when local_delivery set to user’s mailboxes. With first incoming email it creates /Maildir folder in the user home directory but all incoming mail will be frozen in queue and never delivered.

This is example of the error in Exim log file:

2013-02-09 07:33:08 1U49cB-0000A6-6a DKIM: d=yahoo.com s=s1024 c=relaxed/relaxed a=rsa-sha256 t=1360413156 [verification succeeded]
2013-02-09 07:33:08 1U49cB-0000A6-6a <= xxxx@??? H=nm14-vm0.bullet.mail.bf1.yahoo.com [98.139.213.164] P=smtp S=2961 id=1360413156.89864.YahooMailNeo@???
2013-02-09 07:33:08 1U49cB-0000A6-6a failed to read delivery status for xxxx@??? from delivery subprocess
2013-02-09 07:33:09 1U49cB-0000A6-6a appendfile transport process returned non-zero status 0x000b: terminated by signal 11
2013-02-09 07:33:09 1U49cB-0000A6-6a == xxxx@??? R=localuser T=local_delivery defer (-1)
2013-02-09 07:33:09 1U49cB-0000A6-6a Frozen

And my exim.conf setting for local delivery:

local_delivery:
driver = appendfile
directory = $home/Maildir
maildir_format
maildir_use_size_file
delivery_date_add
envelope_to_add
return_path_add
group = mail
mode = 0660

Any idea what may cause this? I think I am missing something in my configuration but cannot find out what it may be.

I appreciate all help. Thanks.