The latest public version of firmware for the Trimble NetRS is 1.3-1.  Download links for the installation file and official release notes are linked below:
NetRS-1.3-1.ppc.rpm
1.3-1 Release Notes (pdf)

This release has been formally accepted for general use; it fixes the "Halloween Bug" that caused all NetRS receivers to reboot on 10/31/2010, and would then recur on 20 August 2017.   There are no other changes in this version, so users have plenty of time to install the update.

Configuration files generated by using firmware version 1.3-0 can be used with 1.3-1.  Configuration files generated with versions older than 1.3-0 may also be applied, but it is recommended that users generate new configuration files once this version has been installed that take advantage of the new features (or explicitly disabled). 

Trimble recommends that users not apply configuration files to firmware versions earlier than those used to generate them, although this has been tested with no ill effects observed.  Do so at your own risk.

UNAVCO members who have purchased NetRS receivers through Community Purchases are entitled to warranty codes that will allow the installation of version 1.3-1, dated 10 Dec 2010.  Users who require new codes to extend the warranty period should email repairs@unavco.org with the receiver serial number(s).

Details:

Name        : NetRS
Summary     : Trimble NetRS Full Firmware Package, version 1.3-1
Version     : 1.3-1
Build Date  : Thu Dec  9 19:45:51 2010
License     : (c)2004-2010 Trimble Navigation Limited
Size        : 11497535 bytes

This is a full release RPM package for a Trimble NetRS GPS receiver.

    Firmware Version 1.3-1
    Firmware Date    2010/12/10

To install this release use the NetRS Browser interface to upload
this file onto your NetRS.  Then click the Install button.  The
installation process will take several minutes.

Expected Installation Time : 400 seconds

==========================================================
Trimble NetRS Firmware Version 1.3-1
==========================================================
This is a Minor release that fixes one specific bug:

All previous releases were vulnerable to a problem which could cause
system reboots and other problems approximately every 7 years.  This
most recently occured on 2010-Oct-31.  This firmware fix prevents that
from ever happening again.