For my Nokia N95 I needed an adapter to connect an external microphone can and thus to make audio recordings. I have the cable from adaptare offered here, and to a second parallel ordered from another company. Both cables look quite similar, with sockets in pink and light green.
The adaptare cable worked immediately, and the N95 gave me as uses "headset, headphones, TV out, Music Station". The other cable came the error message "accessory not supported" when I joined it to the phone.
Optical cables are quite similar. The cable shown in the negative video review is not of adaptare, but what did not work well with me. On adaptare cable small rectangular symbols for headphones and microphone are embedded into plastic.
So if you need something, then here!