your wireless card is probably just creating noise on the PCI bus or something.
"when I was playing the audio back through the firepod" does it happen when you play the audio back through anything else? is it the playback or the recording that has the noise?
OP: have you tried any other programs? (its probably easier to quickly check that before fiddling with hardware)
maybe you should try formatting, installing audio drivers, and try recording. if no clicks, install devices one by one, untill the clicking happens again. bingo, you have found what is responsible. (annoying of the clicks are present straight away though, huh?
)