MY MASTER BROWSER IS…

When looking at the following msg in the NT4.0 Event Viewer…I find my self confused. Can someone enlighten me on what is going on???

The error message:
The Master Browser has received a server announcement from the computer (has been 4 different computer names) that believes it is the Master Browser for the domain on transport NwlnkNb. The master browser is stopping or an election is being forced.

Some info on my setup:
We have 10 workstations running Win98 and the server is Win NT 4.0 What is happening here????