The spinning wheel in the menu bar only reports network activy, when traffic crosses a certain threshold - by default more than 1000 bytes/second (configurable).
This behaviour tries to roughly emulate the way the spinning wheel on the iphone works which also doesnt spin for 'background noise'.
##License iTrafficIndicator uses portions of the open source application 'MenuMeters' to gather detailed network information. This App was previously released to and and published on the appstore with the permission of the original author Alex Harper. #It is now available under GPL