I also have the same problem, I using avast BPP installed on XP SP3
avast! AC: 1.0.888.19
Mirror info, Program ver.: 6.0.1253
Client Ver: 6.0.1253
service in client running and no problem, check on computer audit trial no found any error.
restart client service is not solve the problem, but after restart the PC was appear with green.
I do restart the administration console is also not solve the problem. Once i found error on the computer audit trial with status "Server Error" and I restart it again then the problem solve for about 3 hours then one by one the client look disconnected from administration console.
I have 12 server always up, but on the administration console look disconnected icon.