8003MRxSmbNoneThe master browser has received a server announcement from the computer NT29 that believes that it is the master browser for the domain on transport NetBT_Tcpip_{492C50E8-6A5F-48B9-BA. The master browser is stopping or an election is being forced.
This event can be ignored in almost all cases. It simply indicates that more than one computer in a broadcast network believe that they are the master browser, and that an election is being forced to determine which computer will end up being the master browser.
This commonly happens when you connect a laptop to a corporate network, since the laptop was the master browser for its home network for example.
The computer browser service is, according to Microsoft, depreciated with the introduction of Active Directory, but is still used and activated by default in Windows Server 2003 and earlier.