On a number of machines now, when updating the agent to 6.1 the agent has gone offline and not come back online.
On a few machines this meant I had to connect through other means and reboot the machine. That's okay for servers, but a real problem for client machines.
For another machine I had to move the KaseyaD.ini from c:\prog..files\Kaseya\Agent to a new directory that is created with when I updated the agnet and it's starts with the first couple of digits of my license code.
This is something to watch for as in some cases this may leave you trying to get to a site or re-installing an agent and loosing all your settings.