White noise

I am new Skype user. The few other Skype contacts that I have all are deafened by 'white noise' when linked to me. They do not have this problem with other Skype contacts. I do not experience the noise. I have Logitek webcam, I use XP. My ISP is Tiscali at 1MB B/band. Tiscali suggests disabling my firewall. Does this sound reasonable? Any other comments or advice?

if you record speech from your mic with Sound Recorder is it present ? how about the test call on Skype that plays back to you.

The advice from Tiscali makes no sense.

Thanks to Yarwell for reply. Yes I can record my voice and play back with no noise. I experience no problems with the Skype test call. If I disable the webcam and configure using the separately supplied microphone, recipients still get the white noise.
I also thought the advice from Tiscali to disable my Firewall was nonsense.