[Mailman-Users] i search what is this error of mailman ???

[b.vergondy at approche.net]

hello world !!!
my server send this mail to Postfix all minutes and i search what is this error 
if you have see this error a day... explain me what is the procedure to repair this!!!
 
 
mail 1 : 
mailman -> postfix

Traceback (most recent call last):
  File "/var/lib/mailman/cron/gate_news", line 222, in ?
    main()
  File "/var/lib/mailman/cron/gate_news", line 198, in main
    lock.lock(timeout=0.5)
  File "/home/vdanen/tmp/mailman-buildroot/var/lib/mailman/Mailman/LockFile.py", line 219, in lock
  File "/home/vdanen/tmp/mailman-buildroot/var/lib/mailman/Mailman/LockFile.py", line 350, in __write
IOError: [Errno 13] Permission denied: '/var/lib/mailman/locks/gate_news.lock.www.approche.net.23108'

mail 2
mailman -> postfix

Traceback (most recent call last):
  File "/var/lib/mailman/cron/qrunner", line 276, in ?
    lock.lock(timeout=0.5)
  File "/home/vdanen/tmp/mailman-buildroot/var/lib/mailman/Mailman/LockFile.py", line 219, in lock
  File "/home/vdanen/tmp/mailman-buildroot/var/lib/mailman/Mailman/LockFile.py", line 350, in __write
IOError: [Errno 13] Permission denied: '/var/lib/mailman/locks/qrunner.lock.www.approche.net.23095'

thank for your help...