I am using Xubuntu, Lubuntu and Kubuntu all 12.10

Over several years I have regularly tested my port security using Gibson Shields UP (www.grc.com) and all ports have shown as being Stealthed - until recently, when I have started getting several ports showing as Closed not Stealthed (ports 136-138, 593 and others). Can anyone tell me why this should change and what I can do about it please.

Any suggestions would be very much appreciated.