These issuaes are due to my real world incompatability. I don't blame Sony as this was meant for their specific handsets but as we are buying this for use with many PMP's and units, it should be noted.
I haven't plugged it into any others yet. It may be happening due to the three prongs on my iphone jack not working well with the IEM's. I use it with my desktop unit with none of these problems so that is where my hypothesis starts, an error or random signal generated from the controller and sent to the iphone causing weird control glitches. It only happned twice yesterday. A bigger part is that while walking or just out and about, there will be those tiny pops, it may be the headphone jack of my iphone not playing nice with the IEM's male 3.5mm plug and when it moves around causes these problems.
Again, I agree that incompatibility issues should definitely be noted. But let me throw this out there... Is it possible you received a defective unit or that the jack on your 4S is slightly faulty?
BTW, after a bit more digging around, if you look at the Sony Store website, click on the Specifications tab for the MH1C's. It lists compatibility with Apple cell phones for "Answer, Listen, and Talk" functions. Strange, since this is different than their sales sheet.
One way or another, it doesn't affect me personally, but I think it's good to have a definitive answer for the benefit of other iPhone users.