Plesk installer doesn't delete entries in sources.list

[P_heck]

Hello,

for the third time, I am now spotting the same problem:

Nightly security updates didn't work with following error:

Mar  9 04:47:17 srv2 cron-apt: 36 upgraded, 0 newly installed, 0 to remove and 1 not upgraded.
Mar  9 04:47:17 xxx cron-apt: Need to get 2797 kB/24.5 MB of archives.
Mar  9 04:47:17 xxx cron-apt: After this operation, 265 kB of additional disk space will be used.
Mar  9 04:47:17 xxx cron-apt: WARNING: The following packages cannot be authenticated!
Mar  9 04:47:17 xxx cron-apt:   log4cpp-plesk psa-logrotate psa-spf2 sw-libmilter sw-libpoco
Mar  9 04:47:17 xxx cron-apt:   sw-mariadb-client
Mar  9 04:47:17 xxx cron-apt: E: There are problems and -y was used without --force-yes

It figured out, that Plesk installer temporarily inserts additional sources during installation to the /etc/apt/sources.list file, but is not deleting them in some cases which is breaking the automatic update.

## This is temporary appended by Autoinstaller for
## specify source of product's packages for APT.
deb http://autoinstall.plesk.com/debian/PSA_12.0.18 wheezy all
deb http://autoinstall.plesk.com/debian/SITEBUILDER_12.0.7 all all
deb http://autoinstall.plesk.com/debian/BILLING_12.0.18 all all

Think this needs to be added (if not yet done) to the bug tracking system (didn't found any related post in the forum).

System information:
Debian: Linux xxx 3.2.0-4-amd64 #1 SMP Debian 3.2.65-1+deb7u2 x86_64 GNU/Linux
PLESK: 12.0.18 Update #37

Ciao Peter