I've got the problem, that on some clients the Kaseya Windows Agent system tray icon is missing after booting the system.
I already read this article: http://community.kaseya.com/kb/w/wiki/what-do-i-do-if-the-kaseya-windows-agent-system-tray-icon-is-missing.aspx
Unfortunatly I tried everything what's describe there, but nothing happened.
Thanks in advance!
You can disable the agent icon and then re-enable it. This has corrected the issue for me before. Go to Agent>Agent Menu and on the machine(s) in question uncheck the Enable Agent Icon. Wait a few minutes to allow the machine to check in and update a few times, and then go back in and enable the icon.
Also, on the article you read for this problem, did you verify that the kausrtsk.exe was running as the logged in user? I know you said you tried everything listed, but just checking.