The computer side bar shows 2 icons that informs you about the connection status.
(http://www.efmer.eu/boinc/boinc_tasks/images/icon_not_connected.gif) There is no connection.
(http://www.efmer.eu/boinc/boinc_tasks/images/icon_connection_lost.gif) There was a connection but now it's lost.
Clicking on the computer tab gives you some more information about a computer with no connection.
To reconnect:
Click on "all computers" in the computer sidebar or click on a single computer that you like to reconnect. This will start a reconnect sequence.
If you want BoincTasks to try reconnecting on a continues basis, set up a reconnect: Settings BoincTaks - > Extra and fill in 120 in the "= Reconnect every xx seconds".
This will autoconnect every 2 minutes. The downside is that this takes time and may slow down the viewing.
More information about why a connection is lost can be found in the computers tab.
You want more information in the logging?
Change the log.xml in C:\Program Files\eFMer\BoincTasks\log
Set this option: <connecting> 1 </connecting>
You find a copy of log.xml in C:\Program Files\eFMer\BoincTasks\examples\log , copy the file to C:\Program Files\eFMer\BoincTasks\log and restart BoincTasks.