Unattended Assist installations not staying connected

Unattended Assist installations not staying connected

Hi,

Has anybody else had the issue where after installing the unattended client, the computer very rarely, or mostly never actually shows as available.
This is the same situation on many PC's for me, and I know they are online as I have been able to get remote access using the manual remote session without issue.
I'm using Windows 8.1 with Firefox and the Firefox Plugin, client PC's are a mixture of Windows 7 and Windows 8.1 machines.

Any help will be much appreciated.

Thanks