The Groundwork Open Source Monitor Installation Guide mentions:

Step 6 - Network Configuration
1. MySQL uses the localhost entry in /etc/hosts. Make sure that the localhost entry looks like the example below.
Also, make sure that localhost is first after the IP address followed by localhost.localdomain. Replace
192.168.2.100 with the IP address of the system, and groundworkserver with the real Host name. Example:
groundworkserver.mycompany.com is the fully qualified domain name where the GroundWork Monitor server is
installed. Also, make sure TCP port 3306 is not blocked by your firewall rules. This port is for communication to the
MySQL server.
127.0.0.1 localhost localhost.localdomain
192.168.2.100 groundworkserver groundworkserver.mycompany.com

This requirement for an incorrect /etc/hosts format is wrong, if this only to deal with the bug in MySQL this should not be required by Groundwork Open Source Monitor.

To quote Gabor Gombas and Christoph Haas in the discussion on the Debian Devel mailing list about this issue with MySQL:

On Fri, Sep 23, 2005 at 08:01:05PM +0200, Christoph Haas wrote:
> It appears like MySQL does that. It seems to check the IP address of the
> connecting client to find the permissions in it's internal `users`
> table. So it sees "127.0.0.1" and looks up "localhost.localdomain" which
> it cannot find since it expects "localhost".

Well, I don't think it's MySQL that expects "localhost", it's more like
you have added users in the form of "user@localhost" instead of
"[email protected]". These two forms are _not_ the same as far
as MySQL is concerned.

Ok, after a quick googling I found that this bug has already been
reported for MySQL: http://bugs.mysql.com/11822 and is fixed in MySQL
5.0.11. So if it bothers you, you should upgrade.

http://lists.debian.org/debian-devel/2005/09/msg01149.html

Since Groundwork Open Source Monitor requires MySQL >= 5.0.18, this MySQL bug should not be an issue.

Unless other components of Groundwork Open Source Monitor require the /etc/hosts file to be in this incorrect format, the user should not be required to change his /etc/hosts file to an incorrect format.