i have upgrade my otrs system from versione 3.1.1 to 3.2.4 with this extensions:
ITSM
SystemMonitoring
The Upgrade process is successful, but now when otrs receives an email from Nagios (Monitoring System) the PostMasterMailbox.pl return this error:
ERROR: OTRS-otrs.PostMasterMailbox.pl-10 Perl: 5.8.8 OS: linux Time: Tue Apr 9 09:20:02 2013
Message: Need TicketID!
Traceback (27929):
Module: Kernel::System::Ticket::Event::NagiosAcknowledge::Run (v1.12) Line: 50
Module: Kernel::System::EventHandler::EventHandler (OTRS 3.2.4) Line: 240
Module: Kernel::System::Ticket::TicketLockSet (OTRS 3.2.4) Line: 3592
Module: Kernel::System::PostMaster::FollowUp::Run (OTRS 3.2.4) Line: 81
Module: Kernel::System::PostMaster::Run (OTRS 3.2.4) Line: 360
Module: Kernel::System::MailAccount::POP3::Fetch (OTRS 3.2.4) Line: 196
Module: Kernel::System::MailAccount::MailAccountFetch (OTRS 3.2.4) Line: 419
Module: main::Fetch (unknown version) Line: 177
Module: /opt/otrs/bin/otrs.PostMasterMailbox.pl (unknown version) Line: 90
I tried to remove and reinstall SystemMonitoring module, but the problem is not resolve

Any suggestions?