Clicking noise on a iRig Mic H2

Hello. I use a iRig Mic H2 mic, for podcasting, and twice now I got into trouble, during interviews when the mic starting a "clicking" sound on the recording (I use Garageband for Mac Book Pro). This is not due to the metronome, and the clicking can be very rhythmic, to sporadic but repetitive. Please help, since this is a project where I have some important guests and can't have this kind of technical problem happening.