[Resolved] Problem with plugin SpamAssassin

I get the following spurious DnsResolver errors every few minutes. My server server is only active on Ipv4.

Aug 24 17:51:07 paris spamd[28208]: getpeername() on closed socket GEN9 at /usr/lib/perl/5.14/IO/Socket.pm line 251, <GEN48> line 30.
Aug 24 17:51:07 paris spamd[28208]: plugin: eval failed: error closing socket: Descrittore di file errato at /usr/share/perl5/Mail/SpamAssassin/DnsResolver.pm line 185, <GEN48> line 30.
Aug 24 17:51:07 paris spamd[28208]: plugin: eval failed: error closing socket: Descrittore di file errato at /usr/share/perl5/Mail/SpamAssassin/DnsResolver.pm line 568, <GEN48> line 30.

debian 7
i-mscp Codename: Andromeda
SpamAssassin version 3.3.2
running on Perl version 5.14.2

looking on google I found only post regarding a bug, but are related to a previous version
https://issues.apache.org/SpamAssassin/show_bug.cgi?id=6976
but there is no answer

and command spamd -V

SpamAssassin Server version 3.3.2
running on Perl 5.14.2
with SSL support (IO::Socket::SSL 1.76)
with zlib support (Compress::Zlib 2.033)

spamd --ipv4only
ago 24 22:18:04.947 [3131] warn: error creating a DNS resolver socket: Argomento non valido at /usr/share/perl5/Mail/SpamAssassin/DnsResolver.pm line 235.
ago 24 22:18:07.495 [3131] warn: plugin: eval failed: error closing socket: Descrittore di file errato at /usr/share/perl5/Mail/SpamAssassin/DnsResolver.pm line 568.
ago 24 22:18:07.532 [3131] info: spamd: server started on port 783/tcp (running version 3.3.2)
ago 24 22:18:07.532 [3131] info: spamd: server pid: 3131
ago 24 22:18:07.545 [3131] info: spamd: server successfully spawned child process, pid 3135
ago 24 22:18:07.559 [3131] info: spamd: server successfully spawned child process, pid 3136
ago 24 22:18:07.560 [3131] info: prefork: child states: IS
ago 24 22:18:07.560 [3131] info: prefork: child states: II

ps aux | grep spamd
root 3131 0.7 0.7 165372 57660 pts/1 T 22:18 0:00 /usr/bin/perl -T -w /usr/sbin/spamd --ipv4only
root 3135 0.0 0.6 165372 53588 pts/1 T 22:18 0:00 spamd child
root 3136 0.0 0.6 165372 53592 pts/1 T 22:18 0:00 spamd child
root 3295 0.0 0.0 9252 856 pts/1 S+ 22:19 0:00 grep spamd

now

Aug 24 22:25:55 paris spamd[3131]: Use of uninitialized value $selerr in concatenation (.) or string at /usr/share/perl5/Mail/SpamAssassin/SpamdForkScaling.pm line 332.

solved by removing the dns Hetzner and putting dns of Google.