Postgresql error (and service disruption) on Windows

Hi again,
     our support team is reporting cases where postgres connections are
suddenly dropped, but reconnecting again soon everyting is OK.
Environment is PostgreSQL 9.1 on Windows (various versions)
Asfer some research, I found on postgresql log many of these messages
could not reserve shared memory region (addr=02E80000) for child
0000094C: 487
Searching the archives I found a bug fixed with 9.3.x, since I had 9.1,
I migrated to 9.5.6 (standard for new installations). After restarting,
I got the exact same error and response behaviour.
After another search, I stopped F-Secure Antivirus services, and
everything is now going smoothly. So, with the help of a mate that knows
how this antivirus work, we put exceptions to all PostgreSQL directories.
After restarting, the error was back. Nothing in the AV log. Tomorrow
we'll try with adding exclusions to port 5433....

Someone else facing this problem?

Thanks
Moreno.-