[Dovecot] Error: dict: Failed to initialize dictionary 'expire'

[LÉVAI Dániel]

Hi!

Using dovecot-1.1.17, and BDB-4.6.21.
I'm having this error in every two weeks or so. I've running this in a 
crontab:
/usr/local/sbin/dovecot --exec-mail \
  ext /usr/local/libexec/dovecot/expire-tool

The expire plugin and tool is working fine, the configuration is ok, and 
I'm using the BDB backend.
What happens in every ~two weeks is dovecot starts to give me this error 
messages:
Error: dict: db_env: Unable to allocate memory for transaction detail
Error: dict: Failed to initialize dictionary 'expire'

Reading thru Oracle's Berkeley DB FAQ:
http://www.oracle.com/technology/products/berkeley-db/faq/db_faq.html#28
"This error means the maximum number of active transactions configured 
for Berkeley DB has been reached [...] When all of the memory available 
in the database environment for transactions is in use, calls to being 
a transaction will fail until some active transactions complete. By 
default, the database environment is configured to support at least 20 
active transactions."

What could be happening here? Why coudn't it finish its transactions? 
After a dovecot restart it works fine :\

Thanks in advance for any hints.

Daniel

-- 
LEVAI Daniel
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