Zen Imaging: How does it work?

As odd as this may sound....

I've recently inherited a working Zen network. The stations use Zen7
Imaging to manage new and damaged stations. However there is a step which
occurs that I don't fully understand, nor do I understand what is
happening at this step especially if it goes wrong and was hoping someine
could walk me through it...

When the machine boots up, the first time up it cycles through a Linux
boot process. apparently gets a DHCP address then contacts the Zen
server. It seems at that point to be checking something on the Zen server
and/or partition layout, then if successful (?) the machine reboots again
and it starts up as if normal. If there is any breakdown in
communications, such as the machine being unable to reach the network or
bad cable, etc. the machines will cycle around the linux boot process and
never clear out to Win98.

In fact, the existing employees have a workaround to this; they will use
a Win98 boot disc and repair the boot sector with a FDISK /MBR command.
Obviously this replaces the lilo/grub boot loader and simply allows the
Win98 partition to boot, but I'd like to understand what is happening
during the whole process so I can better understand the proper way to fix
it if something goes wrong.

Mike