Forgotten: So... Tried my PC headphones (Sennheiser PC350's) and while I can't hear the pop with nothing playing, I can hear it when I play audio.
Also tried the Samsung earphones on my iPod touch and the pops weren't present.
Sorry if you've mentioned it before. What app are you using to play your media? And did you try another app to see if it's consistent i.e. hardware as opposed to a fault with the software.
I'll give it a try (the app) using my Denon AHD1001 headphones and my Sony ear bud headphones.