Not sure if this should be in the OpenNMS bugs or OTRS, but OTRS doesn't list the module in their bugzilla and the Vendor in the package list is "OpenNMS" so...
With a new clean install of OTRS 2.4.5 on a new clean install of CentOS 5.4 one gets an error when trying to follow the steps in:
http://www.opennms.org/wiki/OTRS_Trouble_Ticket_Integration

Specifically when one attempts to Install the "OpenNMS Integration Module" within the OTRS Package Manager:
===============================
Software error:

Supported versions:

BEGIN failed--compilation aborted at /usr/lib/perl5/vendor_perl/5.8.8/SOAP/Lite.pm line 3414.
Compilation failed in require at /usr/lib/perl5/vendor_perl/5.8.8/SOAP/Constants.pm line 13.
BEGIN failed--compilation aborted at /usr/lib/perl5/vendor_perl/5.8.8/SOAP/Constants.pm line 13.
Compilation failed in require at /usr/lib/perl5/vendor_perl/5.8.8/SOAP/Lite.pm line 3372.
BEGIN failed--compilation aborted at /usr/lib/perl5/vendor_perl/5.8.8/SOAP/Lite.pm line 3372.

For help, please send mail to the webmaster (root@localhost), giving this error message and the time and date of the error.
Content-Type: text/html; charset=utf-8; Content-Disposition: filename="AdminPackageManager.html" X-Powered-By: OTRS 2.4.5 - Open Ticket Request System (http://otrs.org/) Expires: Tue, 1 Jan 1980 12:00:00 GMT Cache-Control: no-cache Pragma: no-cache
[ OTRS ] Admin OTRS (root@localhost) 02:17:20 - 10/27/2009

Error: Sorry, can't install package, because module SOAP::Lite v0.1 is required and not[..]
Comment:
Bug Report:
Traceback: ERROR: OTRS-CGI-10 Perl: 5.8.8 OS: linux Time: Tue Oct 27 02:17:21 2009

Message: Sorry, can't install package, because module SOAP::Lite v0.1 is required and not installed!

Traceback (17324):
Module: Kernel::System::Package::_CheckModuleRequired (v1.106) Line: 2012
Module: Kernel::System::Package::PackageInstall (v1.106) Line: 374
Module: Kernel::Modules::AdminPackageManager::_InstallHandling (v1.81) Line: 1392
Module: Kernel::Modules::AdminPackageManager::Run (v1.81) Line: 670
Module: Kernel::System::Web::InterfaceAgent::Run (v1.43.2.1) Line: 819
Module: /opt/otrs/bin/cgi-bin/index.pl (v1.88) Line: 48
===============================
However, all requisite steps regarding the OTRS SOAP user setup have been executed successfully, SOAP::Lite and SOAP::DateTime are both installed:
perl-SOAP-Lite-0.710.08-1.el5.rf
perl-SOAP-DateTime-0.02-1.2.el5.rf
...and the OTRS otrs.checkModules utility validates fine.
Finding little reference to this online except a couple of very recent forum posts from other people with no solutions.